| 表1
  イトウの体長 |  |  |  |  |  |  |  |  |  |  |  |  |  | 
 
  | 体長cm | 100 | 90 | 80 | 70 | 60 | 50 | 40 | 30 | 20 | 10 | 総計 匹 | 総計cm | 平均cm |  |  | 
 
  | 1994 | 0 | 0 | 1 | 2 | 3 | 4 | 12 | 6 | 4 | 0 | 32 | 1471 | 46.0 |  |  | 
 
  | 1995 | 0 | 0 | 3 | 3 | 8 | 21 | 8 | 17 | 15 | 4 | 79 | 3538 | 44.8 |  |  | 
 
  | 1996 | 0 | 0 | 1 | 3 | 8 | 9 | 12 | 17 | 15 | 4 | 69 | 2846 | 41.2 |  |  | 
 
  | 1997 | 0 | 0 | 0 | 5 | 14 | 24 | 30 | 13 | 7 | 0 | 93 | 4503 | 48.4 |  |  | 
 
  | 1998 | 0 | 1 | 0 | 15 | 13 | 19 | 18 | 16 | 9 | 3 | 94 | 4733 | 50.4 |  |  | 
 
  | 1999 | 0 | 1 | 3 | 6 | 4 | 25 | 16 | 25 | 8 | 0 | 88 | 4212 | 47.8 |  |  | 
 
  | 2000 | 0 | 2 | 3 | 9 | 26 | 12 | 14 | 25 | 11 | 2 | 104 | 5244 | 50.4 |  |  | 
 
  | 2001 | 0 | 2 | 4 | 5 | 13 | 13 | 19 | 20 | 8 | 1 | 85 | 4178 | 49.1 |  |  | 
 
  | 2002 | 0 | 1 | 6 | 5 | 13 | 15 | 23 | 22 | 14 | 1 | 100 | 4796 | 48.0 |  |  | 
 
  | 2003 | 0 | 1 | 8 | 10 | 13 | 17 | 26 | 16 | 17 | 0 | 108 | 5350 | 49.5 |  |  | 
 
  | 2004 | 1 | 0 | 4 | 10 | 12 | 15 | 18 | 20 | 18 | 1 | 99 | 4704 | 47.5 |  |  | 
 
  | 2005 | 0 | 0 | 2 | 10 | 12 | 13 | 15 | 9 | 4 | 0 | 65 | 3454 | 53.1 |  |  | 
 
  | 2006 | 0 | 1 | 4 | 8 | 11 | 9 | 9 | 8 | 7 | 1 | 58 | 3087 | 53.2 |  |  | 
 
  | 2007 | 0 | 1 | 6 | 10 | 20 | 11 | 11 | 20 | 4 | 0 | 83 | 4459 | 53.7 |  |  | 
 
  | 2008 | 0 | 1 | 5 | 17 | 18 | 14 | 18 | 10 | 10 | 0 | 93 | 5040 | 54.2 |  |  | 
 
  | 2009 | 0 | 2 | 3 | 15 | 7 | 18 | 12 | 9 | 3 | 0 | 69 | 3873 | 56.1 |  |  | 
 
  | 2010 | 0 | 0 | 8 | 6 | 19 | 16 | 9 | 6 | 4 | 0 | 68 | 3873 | 57.0 |  |  | 
 
  | 2011 | 1 | 3 | 7 | 16 | 15 | 12 | 13 | 10 | 17 | 0 | 94 | 5087 | 54.1 |  |  | 
 
  | 2012 | 0 | 0 | 10 | 14 | 9 | 14 | 16 | 32 | 25 | 0 | 120 | 5653 | 47.1 |  |  | 
 
  | 2013 | 0 | 1 | 4 | 5 | 13 | 24 | 21 | 30 | 19 | 0 | 117 | 5201 | 44.5 |  |  | 
 
  | 2014 | 0 | 1 | 3 | 12 | 16 | 33 | 20 | 17 | 9 | 0 | 111 | 5710 | 51.4 |  |  | 
 
  | 2015 | 0 | 4 | 5 | 12 | 20 | 27 | 18 | 12 | 3 | 0 | 101 | 5685 | 56.3 |  |  | 
 
  | 2016 | 1 | 2 | 8 | 13 | 18 | 14 | 18 | 6 | 5 | 0 | 85 | 4925 | 57.9 |  |  | 
 
  | 2017 | 0 | 2 | 2 | 12 | 26 | 20 | 16 | 9 | 7 | 1 | 95 | 5181 | 54.5 |  |  | 
 
  | 2018 | 0 | 2 | 5 | 10 | 30 | 18 | 10 | 16 | 11 | 0 | 102 | 5525 | 54.2 |  |  | 
 
  | 2019 | 0 | 0 | 6 | 13 | 13 | 13 | 13 | 15 | 5 | 7 | 85 | 4311 | 50.7 |  |  | 
 
  | 2020 | 0 | 3 | 3 | 11 | 13 | 17 | 11 | 11 | 6 | 0 | 75 | 4100 | 54.7 |  |  | 
 
  | 2021 | 0 | 2 | 1 | 4 | 10 | 16 | 10 | 8 | 1 | 0 | 52 | 2790 | 53.7 |  |  | 
 
  | 2022 | 0 | 0 | 1 | 5 | 7 | 11 | 11 | 9 | 4 | 0 | 48 | 2392 | 49.8 |  |  | 
 
  | 総計 | 3 | 33 | 116 | 266 | 404 | 474 | 447 | 434 | 270 | 25 | 2472 | 125921 | 50.9 |  |  | 
 
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