condition mean min max ZT0-3 31.995709 31.995709 31.995709 ZT4-7 28.8264755 28.8264755 28.8264755 ZT8-11 37.685534000000004 37.685534000000004 37.685534000000004 ZT12-15 25.875249 25.875249 25.875249 ZT16-19 27.6883895 27.6883895 27.6883895 ZT20-23 30.688537500000002 30.688537500000002 30.688537500000002