condition mean min max ZT0-3 17.734947 17.734947 17.734947 ZT4-7 18.4546865 18.4546865 18.4546865 ZT8-11 16.765444 16.765444 16.765444 ZT12-15 13.71564 13.71564 13.71564 ZT16-19 11.323156 11.323156 11.323156 ZT20-23 10.066774 10.066774 10.066774