condition mean min max ZT0-3 170.581672 170.581672 170.581672 ZT4-7 151.627437 151.627437 151.627437 ZT8-11 201.57365349999998 201.57365349999998 201.57365349999998 ZT12-15 218.0939345 218.0939345 218.0939345 ZT16-19 223.02704799999998 223.02704799999998 223.02704799999998 ZT20-23 178.9988555 178.9988555 178.9988555