condition mean min max ZT0-3 19.002715 19.002715 19.002715 ZT4-7 12.0873055 12.0873055 12.0873055 ZT8-11 10.5273465 10.5273465 10.5273465 ZT12-15 12.821128 12.821128 12.821128 ZT16-19 19.1160855 19.1160855 19.1160855 ZT20-23 18.832479999999997 18.832479999999997 18.832479999999997