| Table 3. Estimated stock numbers at age. | ||||||
| Year Age | 1 | 2 | 3 | 4 | 5 | 6 |
| 1997 | 15139 | 6426 | 8923 | 1375 | 339 | 135 |
| 1998 | 13915 | 10746 | 2616 | 2759 | 406 | 110 |
| 1999 | 12392 | 9035 | 5961 | 662 | 589 | 111 |
| 2000 | 7522 | 8280 | 3612 | 1410 | 170 | 142 |
| 2001 | 6181 | 4043 | 2908 | 918 | 249 | 60 |
| 2002 | 10151 | 3731 | 1542 | 565 | 123 | 57 |
| 2003 | 2129 | 5171 | 1139 | 346 | 124 | 31 |
| 2004 | 13185 | 1564 | 1819 | 293 | 93 | 56 |
| 2005 | 6694 | 8315 | 459 | 607 | 78 | 44 |
| 2006 | 8043 | 4239 | 2583 | 144 | 135 | 36 |
| 2007 | 2347 | 3463 | 931 | 517 | 44 | 70 |
| 2008 | 1141 | 753 | 522 | 158 | 126 | 27 |
| 2009 | 3331 | 446 | 141 | 97 | 39 | 18 |
| 2010 | 3141 | 1559 | 137 | 35 | 18 | 9 |
| 2011 | 3969 | 1756 | 449 | 38 | 12 | 6 |
| 2012 | 8414 | 1743 | 334 | 139 | 21 | 8 |
| 2013 | 11380 | 4009 | 667 | 179 | 46 | 15 |
| 2014 | 3892 | 6666 | 1232 | 362 | 108 | 36 |
| 2015 | 2039 | 1353 | 2141 | 836 | 225 | 90 |
| 2016 | 279 | 669 | 658 | 890 | 444 | 156 |
| 2017 | 3993 | 205 | 256 | 308 | 338 | 162 |
| 2018 | 515 | 2112 | 60 | 138 | 186 | 318 |