condition mean min max ZT0-3 17.534601 17.534601 17.534601 ZT4-7 18.0989295 18.0989295 18.0989295 ZT8-11 18.871712 18.871712 18.871712 ZT12-15 14.357787 14.357787 14.357787 ZT16-19 13.4460435 13.4460435 13.4460435 ZT20-23 13.2505885 13.2505885 13.2505885