condition mean min max ZT0-3 18.83435 18.83435 18.83435 ZT4-7 15.51135 15.51135 15.51135 ZT8-11 14.2486 14.2486 14.2486 ZT12-15 13.77075 13.77075 13.77075 ZT16-19 15.32365 15.32365 15.32365 ZT20-23 19.72285 19.72285 19.72285