condition mean min max ZT0-3 10.15 10.15 10.15 ZT4-7 4.3 4.3 4.3 ZT8-11 12.75 12.75 12.75 ZT12-15 24.45 24.45 24.45 ZT16-19 16.6 16.6 16.6 ZT20-23 9.4 9.4 9.4