condition mean min max ZT0-3 7.869578831 7.858712771 7.880444891000001 ZT4-7 5.44471577375 4.949451591 5.9399799565 ZT8-11 5.8304619815 5.2849888285 6.3759351345 ZT12-15 5.3035239139999995 5.167582976499999 5.4394648514999995 ZT16-19 4.11530722 4.0836867990000005 4.1469276409999996 ZT20-23 4.62718339425 4.467576629 4.7867901595