condition mean min max ZT0-3 6.968965000000001 6.59128 7.34665 ZT4-7 4.28824 4.28824 4.28824 ZT8-11 3.61831 3.61831 3.61831 ZT12-15 0 0 0 ZT16-19 5.183775 5.183775 5.183775 ZT20-23 6.99045 6.99045 6.99045