condition mean min max ZT0-3 1.2076008333333332 1.071758 1.46987 ZT4-7 0.46894250000000004 0.46894250000000004 0.46894250000000004 ZT8-11 0.479283 0.479283 0.479283 ZT12-15 1.4680577499999998 1.3940204999999999 1.542095 ZT16-19 0.8117354999999999 0.8117354999999999 0.8117354999999999 ZT20-23 1.10979 1.10979 1.10979