condition mean min max ZT0-3 3.0317937315 2.991017638 3.072569825 ZT4-7 2.41752325825 2.3153937855 2.519652731 ZT8-11 3.650178683 2.9957166805 4.3046406855 ZT12-15 4.580715195749999 3.638425378 5.523005013499999 ZT16-19 5.37632377175 5.002536606 5.7501109375 ZT20-23 4.97819924275 4.7549886525 5.2014098330000005