condition mean min max ZT0-3 13.131206666666667 11.69262 13.96695 ZT4-7 10.995750000000001 10.995750000000001 10.995750000000001 ZT8-11 10.219355 10.219355 10.219355 ZT12-15 18.29995 16.325499999999998 20.2744 ZT16-19 16.812649999999998 16.812649999999998 16.812649999999998 ZT20-23 17.97475 17.97475 17.97475