condition mean min max ZT0-3 8.8777075 7.565625000000001 10.18979 ZT4-7 7.118595 7.118595 7.118595 ZT8-11 4.34344 4.34344 4.34344 ZT12-15 0 0 0 ZT16-19 8.32549 8.32549 8.32549 ZT20-23 9.14558 9.14558 9.14558