condition mean min max ZT0-3 15.850000000000001 15.850000000000001 15.850000000000001 ZT4-7 14.7 14.7 14.7 ZT8-11 37.0 37.0 37.0 ZT12-15 16.3 16.3 16.3 ZT16-19 19.5 19.5 19.5 ZT20-23 23.15 23.15 23.15