condition mean min max ZT0-3 9.95 9.95 9.95 ZT4-7 8.3 8.3 8.3 ZT8-11 18.6 18.6 18.6 ZT12-15 13.55 13.55 13.55 ZT16-19 7.4 7.4 7.4 ZT20-23 10.3 10.3 10.3