condition mean min max ZT0-3 7.65019 7.65019 7.65019 ZT4-7 7.12664 7.12664 7.12664 ZT8-11 4.3313299999999995 4.3313299999999995 4.3313299999999995 ZT12-15 3.84884 3.84884 3.84884 ZT16-19 7.757375 7.757375 7.757375 ZT20-23 6.68733 6.68733 6.68733