| Table 3. Estimated stock numbers at age. | ||||||
| Year Age | 1 | 2 | 3 | 4 | 5 | 6 |
| 1997 | 16081 | 6319 | 8980 | 1420 | 333 | 135 |
| 1998 | 13329 | 11169 | 2699 | 2744 | 392 | 113 |
| 1999 | 13300 | 8920 | 5856 | 692 | 584 | 110 |
| 2000 | 7197 | 8456 | 3660 | 1415 | 166 | 146 |
| 2001 | 6293 | 4266 | 3030 | 876 | 259 | 60 |
| 2002 | 11243 | 3907 | 1614 | 626 | 132 | 58 |
| 2003 | 2741 | 6415 | 1344 | 398 | 154 | 39 |
| 2004 | 17132 | 1819 | 2181 | 342 | 113 | 64 |
| 2005 | 8667 | 10146 | 554 | 691 | 95 | 52 |
| 2006 | 8910 | 4990 | 3004 | 164 | 170 | 42 |
| 2007 | 2385 | 4002 | 1090 | 591 | 50 | 75 |
| 2008 | 1353 | 892 | 602 | 195 | 133 | 31 |
| 2009 | 4299 | 545 | 168 | 110 | 42 | 23 |
| 2010 | 4176 | 1986 | 164 | 43 | 21 | 11 |
| 2011 | 5059 | 2142 | 566 | 50 | 14 | 8 |
| 2012 | 11590 | 2415 | 452 | 180 | 26 | 10 |
| 2013 | 16994 | 5624 | 860 | 223 | 65 | 18 |
| 2014 | 5111 | 9433 | 1629 | 453 | 130 | 46 |
| 2015 | 3096 | 2089 | 2615 | 940 | 255 | 102 |
| 2016 | 866 | 1249 | 792 | 942 | 424 | 159 |
| 2017 | 4364 | 552 | 446 | 249 | 265 | 142 |
| 2018 | 430 | 1599 | 120 | 143 | 111 | 157 |
| 2019 | 1445 | 168 | 354 | 53 | 32 | 56 |