condition mean min max ZT0-3 15.568964 15.568964 15.568964 ZT4-7 15.7890555 15.7890555 15.7890555 ZT8-11 19.268742 19.268742 19.268742 ZT12-15 15.491478 15.491478 15.491478 ZT16-19 16.355914 16.355914 16.355914 ZT20-23 16.9932565 16.9932565 16.9932565