condition mean min max ZT0-3 9.869787 9.869787 9.869787 ZT4-7 8.605206 8.605206 8.605206 ZT8-11 9.6880465 9.6880465 9.6880465 ZT12-15 9.7105505 9.7105505 9.7105505 ZT16-19 9.4221875 9.4221875 9.4221875 ZT20-23 10.2334995 10.2334995 10.2334995