condition mean min max ZT0-3 10.75 10.75 10.75 ZT4-7 5.1 5.1 5.1 ZT8-11 6.85 6.85 6.85 ZT12-15 28.5 28.5 28.5 ZT16-19 9.65 9.65 9.65 ZT20-23 11.4 11.4 11.4