select left(ar_timestamp, 6) as month, sum(ar_parent_id is not null) as parent, sum(ar_parent_id is null) as null_parent from enwiki.archive group by left(ar_timestamp, 6); month parent null_parent 200101 1 33 200102 10 87 200103 11 106 200104 2 32 200105 6 106 200106 10 79 200107 19 100 200108 17 180 200109 35 417 200110 41 616 200111 77 954 200112 155 1412 200201 73 315 200202 230 1957 200203 163 801 200204 85 603 200205 86 641 200206 84 667 200207 78 1131 200208 102 3399 200209 191 3033 200210 182 3048 200211 170 2739 200212 148 2721 200301 257 4177 200302 207 4773 200303 635 5313 200304 303 5315 200305 406 7105 200306 473 7803 200307 600 10292 200308 659 8170 200309 595 8077 200310 565 7741 200311 841 10414 200312 785 11729 200401 973 12754 200402 1282 24416 200403 2073 31851 200404 2553 28666 200405 2221 32107 200406 3606 67193 200407 3208 55010 200408 4162 62212 200409 4814 78945 200410 4984 81704 200411 5380 99724 200412 6342 131834 200501 5993 107236 200502 5783 101143 200503 7213 125234 200504 8965 146560 200505 10024 171978 200506 11229 189702 200507 13093 218022 200508 15745 255766 200509 13917 231661 200510 16122 302129 200511 20217 318215 200512 24011 406559 200601 27699 443033 200602 26985 462652 200603 32704 540060 200604 31744 526957 200605 34291 611166 200606 38240 601675 200607 40628 635614 200608 48994 706531 200609 41467 635854 200610 47116 674235 200611 47853 704332 200612 49502 697902 200701 52964 775826 200702 53443 760967 200703 56791 811204 200704 75939 1033523 200705 78723 924549 200706 59700 748238 200707 61977 711900 200708 58489 657514 200709 54598 611791 200710 58105 667286 200711 57892 624881 200712 59005 545328 200801 60780 574516 200802 55895 550407 200803 62559 564134 200804 68473 534581 200805 62298 539571 200806 63858 471136 200807 64669 415453 200808 61062 383205 200809 60650 379573 200810 67973 416964 200811 65391 357236 200812 63373 368690 200901 72081 370686 200902 77353 396765 200903 88575 423466 200904 68893 339270 200905 75235 332612 200906 72820 322030 200907 73146 330589 200908 71266 306273 200909 93194 351973 200910 73694 300116 200911 66727 277773 200912 71056 284218 201001 68725 302766 201002 67244 298791 201003 107880 326109 201004 75588 278561 201005 80311 266723 201006 79540 273934 201007 76382 247552 201008 83941 243881 201009 89948 227461 201010 88699 228622 201011 81141 221754 201012 81948 223113 201101 94189 241669 201102 86062 197713 201103 93205 202773 201104 92494 192519 201105 104466 195554 201106 98860 203487 201107 109753 200791 201108 136267 194873 201109 215687 251886 201110 128870 172766 201111 136512 164001 201112 242365 195001 201201 160713 156448 201202 232941 106859 201203 309845 0 201204 264379 0 201205 259117 0 201206 237744 0 201207 288698 0 201208 251621 0 201209 241862 0 201210 296669 0 201211 232980 0 201212 238644 0 201301 249987 0 201302 225995 0 201303 262100 0 201304 245291 0 201305 237154 0 201306 239042 0 201307 238711 0 201308 229396 0 201309 222197 0 201310 212230 0 201311 218885 0 201312 228428 0 201401 236144 0 201402 206745 0 201403 229809 0 201404 203521 0 201405 224732 0 201406 202456 0 201407 207778 0 201408 195934 0 201409 183763 0 201410 195169 0 201411 190964 0 201412 197719 0 201501 205336 0 201502 205543 0 201503 210920 0 201504 197921 0 201505 194026 0 201506 189261 0 201507 192063 0 201508 200083 0 201509 199015 0 201510 193314 0 201511 179937 0 201512 167617 0 201601 174029 0 201602 169088 0 201603 175225 0 201604 156081 0 201605 167086 0 201606 144498 0 201607 135081 0 201608 137951 0 201609 122194 0 201610 113852 0 201611 6168 0