condition mean min max ZT0-3 5.815499999999999 3.3934949999999997 7.775314999999999 ZT4-7 1.256156 1.256156 1.256156 ZT8-11 7.184035 7.184035 7.184035 ZT12-15 15.194625 12.07395 18.3153 ZT16-19 21.5814 21.5814 21.5814 ZT20-23 23.4277 23.4277 23.4277