condition mean min max ZT0-3 20.349999999999998 20.349999999999998 20.349999999999998 ZT4-7 2.8 2.8 2.8 ZT8-11 17.650000000000002 17.650000000000002 17.650000000000002 ZT12-15 9.0 9.0 9.0 ZT16-19 28.3 28.3 28.3 ZT20-23 18.7 18.7 18.7