condition mean min max ZT0-3 66.623959 66.623959 66.623959 ZT4-7 50.1565315 50.1565315 50.1565315 ZT8-11 38.335758999999996 38.335758999999996 38.335758999999996 ZT12-15 45.7981425 45.7981425 45.7981425 ZT16-19 53.877615500000005 53.877615500000005 53.877615500000005 ZT20-23 71.5423625 71.5423625 71.5423625