condition mean min max ZT0-3 18.940613045 17.70576864 20.175457449999996 ZT4-7 18.0809437425 16.95141719 19.210470295 ZT8-11 12.325622594999999 10.79973363 13.851511559999999 ZT12-15 7.19056853725 7.091079816000001 7.2900572585 ZT16-19 13.278676791999999 10.748575844 15.80877774 ZT20-23 22.29055896 20.91727766 23.66384026