condition mean min max ZT0-3 5.25 5.25 5.25 ZT4-7 2.1 2.1 2.1 ZT8-11 12.6 12.6 12.6 ZT12-15 9.0 9.0 9.0 ZT16-19 18.55 18.55 18.55 ZT20-23 32.2 32.2 32.2