condition mean min max ZT0-3 12.3054425 9.525285 15.0856 ZT4-7 2.7979700000000003 2.7979700000000003 2.7979700000000003 ZT8-11 2.79512 2.79512 2.79512 ZT12-15 0 0 0 ZT16-19 4.2875700000000005 4.2875700000000005 4.2875700000000005 ZT20-23 5.4335249999999995 5.4335249999999995 5.4335249999999995