condition mean min max ZT0-3 9.8 9.8 9.8 ZT4-7 5.5 5.5 5.5 ZT8-11 5.8 5.8 5.8 ZT12-15 20.650000000000002 20.650000000000002 20.650000000000002 ZT16-19 17.0 17.0 17.0 ZT20-23 9.9 9.9 9.9