condition mean min max ZT0-3 15.903509 15.903509 15.903509 ZT4-7 16.615039 16.615039 16.615039 ZT8-11 17.2462795 17.2462795 17.2462795 ZT12-15 16.12844 16.12844 16.12844 ZT16-19 15.755634 15.755634 15.755634 ZT20-23 16.3792285 16.3792285 16.3792285