condition mean min max ZT0-3 9.442935 9.442935 9.442935 ZT4-7 6.4764 6.4764 6.4764 ZT8-11 3.98658 3.98658 3.98658 ZT12-15 4.6284 4.6284 4.6284 ZT16-19 7.9975950000000005 7.9975950000000005 7.9975950000000005 ZT20-23 9.88118 9.88118 9.88118