condition mean min max ZT0-3 17.363964 17.363964 17.363964 ZT4-7 17.860725 17.860725 17.860725 ZT8-11 14.7194915 14.7194915 14.7194915 ZT12-15 15.061148 15.061148 15.061148 ZT16-19 17.0423935 17.0423935 17.0423935 ZT20-23 17.377714500000003 17.377714500000003 17.377714500000003