condition mean min max ZT0-3 14.153974999999999 13.3507 14.95725 ZT4-7 20.018099999999997 20.018099999999997 20.018099999999997 ZT8-11 27.39855 27.39855 27.39855 ZT12-15 0 0 0 ZT16-19 4.78831 4.78831 4.78831 ZT20-23 9.801845 9.801845 9.801845