condition mean min max ZT0-3 20.551125 19.9652 21.137050000000002 ZT4-7 36.41935 36.41935 36.41935 ZT8-11 48.6412 48.6412 48.6412 ZT12-15 0 0 0 ZT16-19 42.2101 42.2101 42.2101 ZT20-23 31.264899999999997 31.264899999999997 31.264899999999997