condition mean min max ZT0-3 9.2 9.2 9.2 ZT4-7 9.2 9.2 9.2 ZT8-11 42.4 42.4 42.4 ZT12-15 20.05 20.05 20.05 ZT16-19 23.049999999999997 23.049999999999997 23.049999999999997 ZT20-23 32.65 32.65 32.65