condition mean min max ZT0-3 11.1 11.1 11.1 ZT4-7 9.2 9.2 9.2 ZT8-11 11.3 11.3 11.3 ZT12-15 11.25 11.25 11.25 ZT16-19 9.8 9.8 9.8 ZT20-23 15.3 15.3 15.3