condition mean min max ZT0-3 6.6 6.6 6.6 ZT4-7 4.0 4.0 4.0 ZT8-11 3.65 3.65 3.65 ZT12-15 6.9 6.9 6.9 ZT16-19 5.75 5.75 5.75 ZT20-23 15.149999999999999 15.149999999999999 15.149999999999999