condition mean min max ZT0-3 10.532808333333334 8.512675 11.7073 ZT4-7 8.802209999999999 8.802209999999999 8.802209999999999 ZT8-11 8.61691 8.61691 8.61691 ZT12-15 11.55395 11.5474 11.560500000000001 ZT16-19 11.207049999999999 11.207049999999999 11.207049999999999 ZT20-23 15.04225 15.04225 15.04225