condition mean min max ZT0-3 4.6 4.6 4.6 ZT4-7 16.9 16.9 16.9 ZT8-11 9.1 9.1 9.1 ZT12-15 18.6 18.6 18.6 ZT16-19 16.2 16.2 16.2 ZT20-23 10.5 10.5 10.5