condition mean min max ZT0-3 23.40461 23.40461 23.40461 ZT4-7 21.467010000000002 21.467010000000002 21.467010000000002 ZT8-11 26.13242 26.13242 26.13242 ZT12-15 10.233574666666668 10.233574666666668 10.233574666666668 ZT16-19 15.474734 15.474734 15.474734 ZT20-23 76.29411 76.29411 76.29411