condition mean min max ZT0-3 1.4773768333333333 0.2871055 2.6192349999999998 ZT4-7 0.5600575 0.5600575 0.5600575 ZT8-11 0.27584200000000003 0.27584200000000003 0.27584200000000003 ZT12-15 0.28171625 0.1965295 0.366903 ZT16-19 0.40973800000000005 0.40973800000000005 0.40973800000000005 ZT20-23 0.7932870000000001 0.7932870000000001 0.7932870000000001