| Table 3. Estimated stock numbers at age. | ||||||
| Year Age | 0 | 1 | 2 | 3 | 4 | 5 |
| 1991 | 149035 | 207516 | 152839 | 45116 | 4442 | 18761 |
| 1992 | 64760 | 95278 | 95895 | 68657 | 17929 | 13150 |
| 1993 | 136778 | 41609 | 44029 | 43077 | 27284 | 17615 |
| 1994 | 193918 | 86769 | 19228 | 19778 | 17119 | 25447 |
| 1995 | 221588 | 121820 | 40097 | 8637 | 7860 | 24124 |
| 1996 | 161534 | 138744 | 56295 | 18012 | 3433 | 18127 |
| 1997 | 134896 | 101120 | 64115 | 25288 | 7158 | 12219 |
| 1998 | 102373 | 83871 | 46729 | 28801 | 10049 | 10982 |
| 1999 | 194113 | 63839 | 38758 | 20991 | 11446 | 11920 |
| 2000 | 172996 | 122825 | 29501 | 17410 | 8342 | 13242 |
| 2001 | 521749 | 111484 | 56759 | 13252 | 6919 | 12233 |
| 2002 | 728072 | 343430 | 51518 | 25497 | 5266 | 10854 |
| 2003 | 762248 | 487201 | 158703 | 23142 | 10132 | 9137 |
| 2004 | 318210 | 518962 | 225142 | 71291 | 9197 | 10921 |
| 2005 | 374094 | 220460 | 239819 | 101136 | 28331 | 11402 |
| 2006 | 380714 | 261487 | 101877 | 107729 | 40191 | 22519 |
| 2007 | 414773 | 266179 | 120836 | 45764 | 42811 | 35541 |
| 2008 | 457421 | 289523 | 123005 | 54281 | 18187 | 44407 |
| 2009 | 694358 | 319452 | 133792 | 55255 | 21571 | 35475 |
| 2010 | 859314 | 488103 | 147623 | 60101 | 21958 | 32331 |
| 2011 | 1068422 | 610362 | 225558 | 66313 | 23884 | 30769 |
| 2012 | 616990 | 766656 | 282056 | 101323 | 26353 | 30975 |
| 2013 | 1506442 | 446600 | 354281 | 126702 | 40266 | 32491 |
| 2014 | 770162 | 1095204 | 206379 | 159146 | 50351 | 41235 |
| 2015 | 580197 | 560798 | 506107 | 92707 | 63245 | 51907 |
| 2016 | 370981 | 421792 | 259152 | 227348 | 36842 | 65263 |
| 2017 | 500356 | 268894 | 194915 | 116413 | 90348 | 57869 |