condition mean min max ZT0-3 2.7051049999999996 2.7051049999999996 2.7051049999999996 ZT4-7 2.098035 2.098035 2.098035 ZT8-11 2.011885 2.011885 2.011885 ZT12-15 3.113345 3.113345 3.113345 ZT16-19 4.301725 4.301725 4.301725 ZT20-23 3.603765 3.603765 3.603765