condition mean min max ZT0-3 4.6 4.6 4.6 ZT4-7 6.7 6.7 6.7 ZT8-11 17.25 17.25 17.25 ZT12-15 3.6 3.6 3.6 ZT16-19 16.1 16.1 16.1 ZT20-23 10.3 10.3 10.3