condition mean min max ZT0-3 11.15 11.15 11.15 ZT4-7 17.1 17.1 17.1 ZT8-11 2.4 2.4 2.4 ZT12-15 15.7 15.7 15.7 ZT16-19 2.8 2.8 2.8 ZT20-23 7.45 7.45 7.45