condition mean min max ZT0-3 1.0090976666666667 0.445147 1.769695 ZT4-7 0.6967075 0.6967075 0.6967075 ZT8-11 1.887555 1.887555 1.887555 ZT12-15 2.3609424999999997 2.057225 2.6646599999999996 ZT16-19 1.5788600000000002 1.5788600000000002 1.5788600000000002 ZT20-23 1.303145 1.303145 1.303145