condition mean min max ZT0-3 6.069363333333333 4.141814999999999 7.458125000000001 ZT4-7 4.9530899999999995 4.9530899999999995 4.9530899999999995 ZT8-11 3.0989050000000002 3.0989050000000002 3.0989050000000002 ZT12-15 6.8533349999999995 5.73252 7.97415 ZT16-19 4.808104999999999 4.808104999999999 4.808104999999999 ZT20-23 6.764135 6.764135 6.764135