| Table 2. Estimated stock numbers. | ||||||||
| Year\Age | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7+ | 
| 1994 | 231886 | 67982 | 18559 | 33057 | 4576 | 218 | 23 | 19 | 
| 1995 | 50514 | 104193 | 47572 | 8563 | 8976 | 1339 | 57 | 9 | 
| 1996 | 159692 | 22427 | 73644 | 22093 | 1981 | 2481 | 286 | 11 | 
| 1997 | 213844 | 76496 | 12572 | 35383 | 4940 | 575 | 560 | 78 | 
| 1998 | 71539 | 103466 | 53852 | 5660 | 8267 | 1280 | 149 | 150 | 
| 1999 | 77265 | 32338 | 74533 | 23766 | 1423 | 2023 | 304 | 80 | 
| 2000 | 51431 | 35668 | 22607 | 32565 | 5384 | 313 | 422 | 81 | 
| 2001 | 94656 | 22948 | 25463 | 9138 | 6811 | 1398 | 67 | 110 | 
| 2002 | 30152 | 42916 | 16523 | 11099 | 1928 | 1611 | 335 | 35 | 
| 2003 | 141775 | 14485 | 32860 | 6967 | 2299 | 505 | 359 | 88 | 
| 2004 | 48291 | 69425 | 11186 | 16136 | 1831 | 575 | 135 | 113 | 
| 2005 | 47858 | 22359 | 53104 | 5464 | 4546 | 533 | 132 | 63 | 
| 2006 | 18328 | 22449 | 15637 | 25034 | 1803 | 1353 | 140 | 44 | 
| 2007 | 8745 | 7630 | 15045 | 8102 | 7444 | 733 | 413 | 54 | 
| 2008 | 79698 | 3788 | 5380 | 6722 | 2558 | 1930 | 245 | 147 | 
| 2009 | 25771 | 33223 | 3815 | 3587 | 2023 | 818 | 441 | 110 | 
| 2010 | 39262 | 11346 | 24490 | 2631 | 1319 | 613 | 207 | 133 | 
| 2011 | 26134 | 16452 | 8057 | 13833 | 1221 | 478 | 142 | 80 | 
| 2012 | 65841 | 11503 | 11270 | 4443 | 4649 | 575 | 134 | 51 | 
| 2013 | 43521 | 28624 | 7945 | 5792 | 1495 | 1452 | 191 | 59 | 
| 2014 | 30977 | 19126 | 19109 | 4069 | 1692 | 379 | 344 | 58 | 
| 2015 | 9718 | 13316 | 13501 | 8827 | 1350 | 460 | 96 | 115 | 
| 2016 | 4419 | 4747 | 9640 | 7844 | 2597 | 468 | 112 | 70 | 
| 2017 | 27255 | 1865 | 3695 | 5484 | 2876 | 942 | 141 | 55 |