condition mean min max ZT0-3 7.20909 5.41696 8.931085 ZT4-7 1.69254 1.69254 1.69254 ZT8-11 4.060345 4.060345 4.060345 ZT12-15 8.2330375 6.9205000000000005 9.545575 ZT16-19 13.05035 13.05035 13.05035 ZT20-23 3.6804249999999996 3.6804249999999996 3.6804249999999996