condition mean min max ZT0-3 37.50855 33.67085 41.34625 ZT4-7 21.6023 21.6023 21.6023 ZT8-11 20.81265 20.81265 20.81265 ZT12-15 0 0 0 ZT16-19 28.110599999999998 28.110599999999998 28.110599999999998 ZT20-23 31.71025 31.71025 31.71025