condition mean min max ZT0-3 19.53885 19.53885 19.53885 ZT4-7 17.579900000000002 17.579900000000002 17.579900000000002 ZT8-11 18.255850000000002 18.255850000000002 18.255850000000002 ZT12-15 19.21985 19.21985 19.21985 ZT16-19 24.862450000000003 24.862450000000003 24.862450000000003 ZT20-23 20.95015 20.95015 20.95015