condition mean min max ZT0-3 24.5 24.5 24.5 ZT4-7 13.3 13.3 13.3 ZT8-11 28.5 28.5 28.5 ZT12-15 17.65 17.65 17.65 ZT16-19 8.5 8.5 8.5 ZT20-23 16.5 16.5 16.5