condition mean min max ZT0-3 7.65 7.65 7.65 ZT4-7 2.9 2.9 2.9 ZT8-11 13.85 13.85 13.85 ZT12-15 8.6 8.6 8.6 ZT16-19 11.8 11.8 11.8 ZT20-23 15.850000000000001 15.850000000000001 15.850000000000001