condition mean min max ZT0-3 15.8 15.8 15.8 ZT4-7 22.1 22.1 22.1 ZT8-11 11.850000000000001 11.850000000000001 11.850000000000001 ZT12-15 31.4 31.4 31.4 ZT16-19 12.7 12.7 12.7 ZT20-23 49.599999999999994 49.599999999999994 49.599999999999994