condition mean min max ZT0-3 13.956266666666666 11.66355 16.0661 ZT4-7 11.772 11.772 11.772 ZT8-11 8.91162 8.91162 8.91162 ZT12-15 14.777 14.1995 15.354499999999998 ZT16-19 13.4012 13.4012 13.4012 ZT20-23 16.2047 16.2047 16.2047