condition mean min max ZT0-3 16.700000000000003 16.700000000000003 16.700000000000003 ZT4-7 11.3 11.3 11.3 ZT8-11 13.850000000000001 13.850000000000001 13.850000000000001 ZT12-15 30.7 30.7 30.7 ZT16-19 9.05 9.05 9.05 ZT20-23 2.95 2.95 2.95