condition mean min max ZT0-3 3.247865 2.467515 3.99484 ZT4-7 1.0387300000000002 1.0387300000000002 1.0387300000000002 ZT8-11 1.3403399999999999 1.3403399999999999 1.3403399999999999 ZT12-15 1.2807632500000001 1.1522165 1.40931 ZT16-19 1.7881900000000002 1.7881900000000002 1.7881900000000002 ZT20-23 0.8674445000000001 0.8674445000000001 0.8674445000000001