condition mean min max ZT0-3 10.5306625 9.668825 11.3925 ZT4-7 12.588000000000001 12.588000000000001 12.588000000000001 ZT8-11 17.4909 17.4909 17.4909 ZT12-15 0 0 0 ZT16-19 18.31595 18.31595 18.31595 ZT20-23 12.54325 12.54325 12.54325