condition mean min max ZT0-3 11.75 11.75 11.75 ZT4-7 25.7 25.7 25.7 ZT8-11 20.4 20.4 20.4 ZT12-15 20.85 20.85 20.85 ZT16-19 5.8999999999999995 5.8999999999999995 5.8999999999999995 ZT20-23 16.85 16.85 16.85