| Table 3. Estimated stock numbers at age. | |||||||
| Year Age | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| 1981 | 9670 | 20322 | 7033 | 1981 | 460 | 58 | 112 |
| 1982 | 23341 | 5092 | 7801 | 2531 | 751 | 192 | 89 |
| 1983 | 14308 | 12023 | 2199 | 2719 | 919 | 278 | 123 |
| 1984 | 23068 | 6544 | 4783 | 757 | 913 | 319 | 160 |
| 1985 | 10561 | 11388 | 2397 | 1454 | 238 | 273 | 182 |
| 1986 | 18945 | 4473 | 4147 | 697 | 378 | 71 | 164 |
| 1987 | 47138 | 9789 | 1731 | 1289 | 216 | 109 | 108 |
| 1988 | 7298 | 20206 | 3676 | 501 | 353 | 63 | 91 |
| 1989 | 20789 | 2901 | 6514 | 1102 | 157 | 103 | 71 |
| 1990 | 8836 | 9239 | 988 | 1649 | 326 | 45 | 67 |
| 1991 | 12177 | 3495 | 3312 | 335 | 466 | 110 | 54 |
| 1992 | 20895 | 4991 | 1064 | 1017 | 113 | 127 | 65 |
| 1993 | 7105 | 9119 | 1723 | 282 | 292 | 37 | 77 |
| 1994 | 13954 | 3272 | 3204 | 479 | 89 | 87 | 52 |
| 1995 | 9621 | 6057 | 1217 | 1003 | 136 | 28 | 51 |
| 1996 | 3910 | 4355 | 1859 | 359 | 298 | 42 | 35 |
| 1997 | 15115 | 1770 | 1359 | 474 | 103 | 90 | 30 |
| 1998 | 5239 | 7130 | 518 | 350 | 128 | 29 | 41 |
| 1999 | 3722 | 2090 | 2005 | 130 | 95 | 38 | 32 |
| 2000 | 12919 | 1596 | 578 | 507 | 35 | 26 | 30 |
| 2001 | 3873 | 5403 | 504 | 163 | 154 | 10 | 23 |
| 2002 | 6638 | 1602 | 1665 | 134 | 40 | 41 | 15 |
| 2003 | 2240 | 2623 | 447 | 461 | 39 | 10 | 18 |
| 2004 | 2940 | 859 | 687 | 101 | 122 | 11 | 11 |
| 2005 | 1769 | 1086 | 233 | 173 | 28 | 29 | 8 |
| 2006 | 6888 | 668 | 358 | 50 | 42 | 7 | 11 |
| 2007 | 1979 | 3119 | 217 | 99 | 10 | 10 | 7 |
| 2008 | 1407 | 735 | 1055 | 53 | 29 | 2 | 6 |
| 2009 | 5272 | 623 | 277 | 235 | 13 | 9 | 4 |
| 2010 | 5335 | 2537 | 264 | 61 | 45 | 2 | 4 |
| 2011 | 2282 | 2555 | 1009 | 59 | 15 | 13 | 3 |
| 2012 | 4269 | 1066 | 1137 | 212 | 13 | 4 | 6 |
| 2013 | 7507 | 1866 | 522 | 331 | 53 | 4 | 4 |
| 2014 | 5973 | 3434 | 834 | 166 | 103 | 15 | 4 |
| 2015 | 5382 | 2666 | 1607 | 243 | 57 | 36 | 7 |
| 2016 | 2391 | 2650 | 1197 | 543 | 78 | 20 | 17 |
| 2017 | 1938 | 1060 | 1366 | 402 | 189 | 27 | 17 |
| 2018 | 1354 | 926 | 436 | 428 | 126 | 63 | 19 |
| 2019 | 2935 | 577 | 395 | 115 | 116 | 34 | 30 |