condition mean min max ZT0-3 1.719855 1.719855 1.719855 ZT4-7 0.8627230000000001 0.8627230000000001 0.8627230000000001 ZT8-11 2.75882 2.75882 2.75882 ZT12-15 5.9364 5.9364 5.9364 ZT16-19 6.141085 6.141085 6.141085 ZT20-23 3.162575 3.162575 3.162575