condition mean min max ZT0-3 3.71424 3.71424 3.71424 ZT4-7 3.19155 3.19155 3.19155 ZT8-11 2.60262 2.60262 2.60262 ZT12-15 1.7462550000000001 1.7462550000000001 1.7462550000000001 ZT16-19 2.4402150000000002 2.4402150000000002 2.4402150000000002 ZT20-23 3.31205 3.31205 3.31205