wikiadmin@10.64.32.76(enwiki)> select count(*), SUBSTR(page_links_updated, 1,6) from page where page_namespace=0 group by SUBSTR(page_links_updated, 1,6) order by SUBSTR(page_links_updated, 1,6) desc;
+----------+---------------------------------+
| count(*) | SUBSTR(page_links_updated, 1,6) |
+----------+---------------------------------+
|  3257972 | 202012                          |
|  2233458 | 202011                          |
|  2536145 | 202010                          |
|   512755 | 202009                          |
|   211674 | 202008                          |
|   179282 | 202007                          |
|   124048 | 202006                          |
|   667914 | 202005                          |
|   258310 | 202004                          |
|   329467 | 202003                          |
|   210547 | 202002                          |
|   165346 | 202001                          |
|   305788 | 201912                          |
|   398984 | 201911                          |
|   325684 | 201910                          |
|   316952 | 201909                          |
|   482041 | 201908                          |
|    53715 | 201907                          |
|    40204 | 201906                          |
|    31363 | 201905                          |
|    74385 | 201904                          |
|    30669 | 201903                          |
|    29192 | 201902                          |
|    35690 | 201901                          |
|    42189 | 201812                          |
|    30314 | 201811                          |
|    36475 | 201810                          |
|    25103 | 201809                          |
|    28847 | 201808                          |
|    34153 | 201807                          |
|    25615 | 201806                          |
|    25739 | 201805                          |
|    29663 | 201804                          |
|    29720 | 201803                          |
|    26932 | 201802                          |
|    29330 | 201801                          |
|    28410 | 201712                          |
|    27558 | 201711                          |
|    44864 | 201710                          |
|    50035 | 201709                          |
|    29398 | 201708                          |
|    28296 | 201707                          |
|   122644 | 201706                          |
|    24709 | 201705                          |
|    26007 | 201704                          |
|    32764 | 201703                          |
|    25752 | 201702                          |
|    28051 | 201701                          |
|    83138 | 201612                          |
|    90421 | 201611                          |
|    25815 | 201610                          |
|    24580 | 201609                          |
|    26164 | 201608                          |
|    25636 | 201607                          |
|    24327 | 201606                          |
|    27531 | 201605                          |
|    29664 | 201604                          |
|    24699 | 201603                          |
|    28703 | 201602                          |
|    26721 | 201601                          |
|    25051 | 201512                          |
|    22859 | 201511                          |
|    25877 | 201510                          |
|    26596 | 201509                          |
|    30165 | 201508                          |
|    29751 | 201507                          |
|    28102 | 201506                          |
|    33128 | 201505                          |
|    26210 | 201504                          |
|    25505 | 201503                          |
|    22539 | 201502                          |
|    24966 | 201501                          |
|    24594 | 201412                          |
|    22626 | 201411                          |
|    20201 | 201410                          |
|    23350 | 201409                          |
|    24948 | 201408                          |
|    29008 | 201407                          |
|    27975 | 201406                          |
|    34198 | 201405                          |
|    24257 | 201404                          |
|    26346 | 201403                          |
|    26221 | 201402                          |
|    21421 | 201401                          |
|      174 | 201312                          |
|      154 | 201311                          |
|      190 | 201310                          |
|      180 | 201309                          |
|      179 | 201308                          |
|      117 | 201307                          |
|      109 | 201306                          |
|      147 | 201305                          |
|      147 | 201304                          |
|       99 | 201303                          |
|       18 | 201302                          |
|       31 | 201301                          |
|       14 | 201212                          |
|        4 | 201211                          |
|        6 | 201210                          |
|        6 | 201209                          |
|        8 | 201208                          |
|        3 | 201207                          |
|        2 | 201206                          |
|       11 | 201205                          |
|        1 | 201204                          |
|        4 | 201203                          |
|        6 | 201202                          |
|        3 | 201112                          |
|        1 | 201111                          |
|        1 | 201110                          |
|        1 | 201109                          |
|        1 | 201108                          |
|        6 | 201107                          |
|        2 | 201105                          |
|        1 | 201104                          |
|        1 | 201103                          |
|        2 | 201102                          |
|        3 | 201101                          |
|        1 | 201012                          |
|        1 | 201011                          |
|        1 | 201010                          |
|        1 | 201009                          |
|        5 | 201008                          |
|        2 | 201007                          |
|        1 | 201006                          |
|        1 | 201005                          |
|        1 | 201004                          |
|        1 | 201002                          |
|        2 | 201001                          |
|   873851 | NULL                            |
+----------+---------------------------------+
130 rows in set (1 min 4.49 sec)