condition mean min max ZT0-3 13.896095 9.306585 16.76885 ZT4-7 8.03686 8.03686 8.03686 ZT8-11 6.263055 6.263055 6.263055 ZT12-15 12.622775 12.017700000000001 13.22785 ZT16-19 14.145399999999999 14.145399999999999 14.145399999999999 ZT20-23 19.6432 19.6432 19.6432