| Table 2. Estimated stock numbers. | ||||||||||
| Year\Age | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10+ |
| 2002 | 3840 | 3805 | 2267 | 299 | 80 | 26 | 22 | 7 | 0 | 13 |
| 2003 | 5712 | 2688 | 1692 | 634 | 81 | 30 | 13 | 7 | 4 | 8 |
| 2004 | 8388 | 4584 | 1790 | 419 | 109 | 24 | 14 | 5 | 5 | 8 |
| 2005 | 5719 | 7052 | 2974 | 835 | 143 | 41 | 15 | 5 | 3 | 8 |
| 2006 | 2726 | 4551 | 4406 | 1875 | 409 | 74 | 25 | 8 | 3 | 7 |
| 2007 | 1978 | 2844 | 2905 | 2197 | 891 | 232 | 44 | 16 | 6 | 7 |
| 2008 | 2965 | 2628 | 2488 | 1504 | 958 | 403 | 138 | 21 | 10 | 7 |
| 2009 | 8114 | 2944 | 2755 | 1805 | 806 | 430 | 195 | 57 | 9 | 11 |
| 2010 | 19266 | 6654 | 2531 | 1558 | 774 | 317 | 173 | 68 | 22 | 13 |
| 2011 | 21019 | 16092 | 4446 | 1119 | 606 | 276 | 133 | 67 | 29 | 20 |
| 2012 | 14004 | 15126 | 8380 | 1564 | 450 | 241 | 123 | 55 | 25 | 31 |
| 2013 | 12806 | 7595 | 7844 | 2641 | 674 | 200 | 94 | 49 | 29 | 36 |
| 2014 | 18239 | 10633 | 3938 | 2442 | 1044 | 295 | 93 | 35 | 19 | 27 |
| 2015 | 29555 | 12827 | 6326 | 1672 | 1185 | 516 | 166 | 56 | 16 | 25 |
| 2016 | 38561 | 18050 | 7257 | 2938 | 1014 | 682 | 282 | 109 | 41 | 30 |
| 2017 | 44936 | 31540 | 10561 | 3934 | 1858 | 756 | 496 | 230 | 81 | 72 |
| 2018 | 50011 | 38101 | 24149 | 6370 | 2949 | 1214 | 566 | 388 | 164 | 149 |