condition mean min max ZT0-3 10.5393 10.5393 10.5393 ZT4-7 6.6345849999999995 6.6345849999999995 6.6345849999999995 ZT8-11 6.4271650000000005 6.4271650000000005 6.4271650000000005 ZT12-15 7.6565449999999995 7.6565449999999995 7.6565449999999995 ZT16-19 12.02395 12.02395 12.02395 ZT20-23 13.68995 13.68995 13.68995