condition mean min max ZT0-3 7.25 7.25 7.25 ZT4-7 11.2 11.2 11.2 ZT8-11 20.0 20.0 20.0 ZT12-15 26.4 26.4 26.4 ZT16-19 13.95 13.95 13.95 ZT20-23 11.25 11.25 11.25