condition mean min max ZT0-3 7.2 7.2 7.2 ZT4-7 2.8 2.8 2.8 ZT8-11 28.65 28.65 28.65 ZT12-15 6.4 6.4 6.4 ZT16-19 10.45 10.45 10.45 ZT20-23 13.3 13.3 13.3