condition mean min max ZT0-3 11.25 11.25 11.25 ZT4-7 10.4 10.4 10.4 ZT8-11 20.2 20.2 20.2 ZT12-15 9.7 9.7 9.7 ZT16-19 28.25 28.25 28.25 ZT20-23 8.5 8.5 8.5