condition mean min max ZT0-3 5.85 5.85 5.85 ZT4-7 7.8 7.8 7.8 ZT8-11 14.6 14.6 14.6 ZT12-15 20.049999999999997 20.049999999999997 20.049999999999997 ZT16-19 23.15 23.15 23.15 ZT20-23 11.2 11.2 11.2