condition mean min max ZT0-3 2.4027125 2.20977 2.595655 ZT4-7 2.015015 2.015015 2.015015 ZT8-11 2.3395200000000003 2.3395200000000003 2.3395200000000003 ZT12-15 0 0 0 ZT16-19 2.8998749999999998 2.8998749999999998 2.8998749999999998 ZT20-23 2.70554 2.70554 2.70554