condition mean min max ZT0-3 4.11676 4.11676 4.11676 ZT4-7 3.62783 3.62783 3.62783 ZT8-11 5.37914 5.37914 5.37914 ZT12-15 4.91308 4.91308 4.91308 ZT16-19 5.909400000000001 5.909400000000001 5.909400000000001 ZT20-23 6.3616399999999995 6.3616399999999995 6.3616399999999995