condition mean min max ZT0-3 3.9326399999999997 2.92394 4.66479 ZT4-7 3.091085 3.091085 3.091085 ZT8-11 3.7557650000000002 3.7557650000000002 3.7557650000000002 ZT12-15 6.39852 5.965785 6.8312550000000005 ZT16-19 5.66365 5.66365 5.66365 ZT20-23 6.184365 6.184365 6.184365