condition mean min max ZT0-3 40.140898 40.140898 40.140898 ZT4-7 20.064616 20.064616 20.064616 ZT8-11 14.736056999999999 14.736056999999999 14.736056999999999 ZT12-15 13.2045005 13.2045005 13.2045005 ZT16-19 12.3280135 12.3280135 12.3280135 ZT20-23 13.8939065 13.8939065 13.8939065