condition mean min max ZT0-3 11.890762500000001 10.351575 13.42995 ZT4-7 6.78972 6.78972 6.78972 ZT8-11 2.73688 2.73688 2.73688 ZT12-15 0 0 0 ZT16-19 7.92626 7.92626 7.92626 ZT20-23 8.41825 8.41825 8.41825