condition mean min max ZT0-3 1.7317749999999998 1.260975 2.202575 ZT4-7 3.08621 3.08621 3.08621 ZT8-11 2.79302 2.79302 2.79302 ZT12-15 0 0 0 ZT16-19 4.81965 4.81965 4.81965 ZT20-23 2.631455 2.631455 2.631455