condition mean min max ZT0-3 21.124125 20.9535 21.29475 ZT4-7 17.012050000000002 17.012050000000002 17.012050000000002 ZT8-11 14.6914 14.6914 14.6914 ZT12-15 0 0 0 ZT16-19 20.231 20.231 20.231 ZT20-23 21.644849999999998 21.644849999999998 21.644849999999998