condition mean min max ZT0-3 7.9738066666666665 6.11115 9.32131 ZT4-7 7.28104 7.28104 7.28104 ZT8-11 6.232585 6.232585 6.232585 ZT12-15 5.7660275 4.64942 6.882635 ZT16-19 9.253265 9.253265 9.253265 ZT20-23 9.427195000000001 9.427195000000001 9.427195000000001