condition mean min max ZT0-3 12.768683333333332 10.79 14.05975 ZT4-7 11.02995 11.02995 11.02995 ZT8-11 7.7840050000000005 7.7840050000000005 7.7840050000000005 ZT12-15 8.2966725 7.507365 9.08598 ZT16-19 7.917865000000001 7.917865000000001 7.917865000000001 ZT20-23 10.696765 10.696765 10.696765