condition mean min max ZT0-3 14.347043333333332 8.45668 17.950899999999997 ZT4-7 9.268515 9.268515 9.268515 ZT8-11 7.85677 7.85677 7.85677 ZT12-15 10.464775 9.479485 11.450064999999999 ZT16-19 11.233550000000001 11.233550000000001 11.233550000000001 ZT20-23 18.67355 18.67355 18.67355