condition mean min max ZT0-3 4.895215 4.895215 4.895215 ZT4-7 3.625915 3.625915 3.625915 ZT8-11 3.378355 3.378355 3.378355 ZT12-15 3.5134600000000002 3.5134600000000002 3.5134600000000002 ZT16-19 5.406745 5.406745 5.406745 ZT20-23 4.742055000000001 4.742055000000001 4.742055000000001