condition mean min max ZT0-3 16.5401 15.26745 17.61915 ZT4-7 10.952605 10.952605 10.952605 ZT8-11 13.71625 13.71625 13.71625 ZT12-15 14.973125 13.4108 16.53545 ZT16-19 21.36305 21.36305 21.36305 ZT20-23 19.2971 19.2971 19.2971