condition mean min max ZT0-3 21.245616666666667 14.36035 25.794249999999998 ZT4-7 10.302575000000001 10.302575000000001 10.302575000000001 ZT8-11 9.706465000000001 9.706465000000001 9.706465000000001 ZT12-15 13.28605 12.8768 13.6953 ZT16-19 9.69896 9.69896 9.69896 ZT20-23 15.971150000000002 15.971150000000002 15.971150000000002