| Table 2. Estimated stock numbers. | ||||||||
| Year\Age | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7+ |
| 1994 | 182956 | 64344 | 18182 | 31445 | 4540 | 221 | 23 | 19 |
| 1995 | 75057 | 87291 | 44936 | 8307 | 8774 | 1354 | 58 | 8 |
| 1996 | 177371 | 30031 | 65513 | 20752 | 1935 | 2414 | 275 | 11 |
| 1997 | 224358 | 83117 | 14415 | 32761 | 4773 | 571 | 550 | 78 |
| 1998 | 89501 | 108880 | 55826 | 6046 | 7971 | 1243 | 153 | 150 |
| 1999 | 83868 | 37987 | 76957 | 23909 | 1524 | 1957 | 306 | 85 |
| 2000 | 59397 | 38369 | 25235 | 32958 | 5390 | 314 | 411 | 82 |
| 2001 | 85991 | 25463 | 27174 | 9861 | 7037 | 1376 | 68 | 111 |
| 2002 | 32893 | 41233 | 17929 | 11439 | 2037 | 1567 | 338 | 36 |
| 2003 | 127389 | 15119 | 33124 | 7395 | 2382 | 510 | 356 | 91 |
| 2004 | 55105 | 66769 | 11525 | 16477 | 1998 | 580 | 141 | 115 |
| 2005 | 46723 | 24686 | 54394 | 5602 | 4864 | 561 | 133 | 65 |
| 2006 | 17365 | 23179 | 16706 | 26370 | 1930 | 1406 | 145 | 43 |
| 2007 | 8357 | 7512 | 15692 | 8479 | 8025 | 787 | 430 | 56 |
| 2008 | 63259 | 3533 | 5440 | 6997 | 2777 | 2010 | 263 | 153 |
| 2009 | 28254 | 28941 | 3856 | 3710 | 2191 | 859 | 432 | 111 |
| 2010 | 42362 | 12154 | 22857 | 2753 | 1451 | 637 | 203 | 123 |
| 2011 | 31039 | 17808 | 8432 | 13057 | 1386 | 505 | 135 | 72 |
| 2012 | 80017 | 12933 | 12280 | 4716 | 4791 | 634 | 133 | 44 |
| 2013 | 56727 | 35882 | 8640 | 6698 | 1766 | 1441 | 204 | 56 |
| 2014 | 45844 | 24959 | 25771 | 4507 | 2397 | 438 | 308 | 54 |
| 2015 | 45844 | 20022 | 18738 | 15034 | 1674 | 805 | 116 | 96 |