condition mean min max ZT0-3 5.69773 5.69773 5.69773 ZT4-7 4.114945 4.114945 4.114945 ZT8-11 4.426785 4.426785 4.426785 ZT12-15 5.60844 5.60844 5.60844 ZT16-19 7.98465 7.98465 7.98465 ZT20-23 6.40332 6.40332 6.40332