condition mean min max ZT0-3 20.9 20.9 20.9 ZT4-7 39.9 39.9 39.9 ZT8-11 26.25 26.25 26.25 ZT12-15 19.8 19.8 19.8 ZT16-19 9.6 9.6 9.6 ZT20-23 21.1 21.1 21.1