condition mean min max ZT0-3 5.930086666666667 4.372 7.023785 ZT4-7 8.63822 8.63822 8.63822 ZT8-11 5.07996 5.07996 5.07996 ZT12-15 3.8298699999999997 2.832925 4.826815 ZT16-19 4.4531 4.4531 4.4531 ZT20-23 3.759955 3.759955 3.759955