condition mean min max ZT0-3 1.7083768333333333 1.3281805 2.04679 ZT4-7 0.6504205000000001 0.6504205000000001 0.6504205000000001 ZT8-11 1.008156 1.008156 1.008156 ZT12-15 0.35006024999999996 0.0 0.7001204999999999 ZT16-19 0.626295 0.626295 0.626295 ZT20-23 1.793135 1.793135 1.793135