condition mean min max ZT0-3 3.496353333333333 2.76525 4.939344999999999 ZT4-7 2.3152049999999997 2.3152049999999997 2.3152049999999997 ZT8-11 2.4499 2.4499 2.4499 ZT12-15 7.4017175 7.385120000000001 7.418315 ZT16-19 4.84615 4.84615 4.84615 ZT20-23 4.68895 4.68895 4.68895