condition mean min max ZT0-3 48.90265 48.90265 48.90265 ZT4-7 40.7612 40.7612 40.7612 ZT8-11 37.61965 37.61965 37.61965 ZT12-15 40.2558 40.2558 40.2558 ZT16-19 46.848600000000005 46.848600000000005 46.848600000000005 ZT20-23 49.25935 49.25935 49.25935