condition mean min max ZT0-3 15.232795 15.232795 15.232795 ZT4-7 14.576175 14.576175 14.576175 ZT8-11 13.627307 13.627307 13.627307 ZT12-15 15.442567 15.442567 15.442567 ZT16-19 12.3837765 12.3837765 12.3837765 ZT20-23 13.581993 13.581993 13.581993