condition mean min max ZT0-3 3.044365 2.551445 3.537285 ZT4-7 2.11103 2.11103 2.11103 ZT8-11 3.20763 3.20763 3.20763 ZT12-15 0 0 0 ZT16-19 2.73306 2.73306 2.73306 ZT20-23 2.43853 2.43853 2.43853