condition mean min max ZT0-3 247.112216 247.112216 247.112216 ZT4-7 209.683849 209.683849 209.683849 ZT8-11 202.8456215 202.8456215 202.8456215 ZT12-15 185.05490550000002 185.05490550000002 185.05490550000002 ZT16-19 266.33471799999995 266.33471799999995 266.33471799999995 ZT20-23 255.54809699999998 255.54809699999998 255.54809699999998