condition mean min max ZT0-3 2.5176600000000002 2.5176600000000002 2.5176600000000002 ZT4-7 1.9662199999999999 1.9662199999999999 1.9662199999999999 ZT8-11 5.281295 5.281295 5.281295 ZT12-15 23.31845 23.31845 23.31845 ZT16-19 9.404516666666666 9.404516666666666 9.404516666666666 ZT20-23 5.51112 5.51112 5.51112