condition mean min max ZT0-3 15.472875 15.13505 15.8107 ZT4-7 13.5393 13.5393 13.5393 ZT8-11 7.854464999999999 7.854464999999999 7.854464999999999 ZT12-15 0 0 0 ZT16-19 12.07185 12.07185 12.07185 ZT20-23 23.902 23.902 23.902