. 17 18 2006 10 . 17 . 0 50 100 150 200 250 H8 H9 H10 H11 H12 H13 H14 H15 H16 H17 H18 H19 H20 H21 H22 H23 H24 H25 53 59 76 72 77 86 91 98 114 112 120 127 136 143 152 159 168 176 43 46 36 36 37 36 35 35 26 26 25 25 25 24 24 24 23 23 96 105 112 108 114 122 126 133 140 138 145 152 161 167 176 183 191 199 0 1,000 2,000 3,000 4,000 5,000 6,000 3,041 3,257 3,179 1,494 1,526 1,785 261 266 285 63.4% 64.5% 60.6% 31.2% 30.2% 34.0% 5.4% 5.3% 5.4% 1/2 1951 . .