condition mean min max ZT0-3 21.192542 21.192542 21.192542 ZT4-7 13.3606955 13.3606955 13.3606955 ZT8-11 12.8460755 12.8460755 12.8460755 ZT12-15 14.6347235 14.6347235 14.6347235 ZT16-19 13.0575615 13.0575615 13.0575615 ZT20-23 13.437771999999999 13.437771999999999 13.437771999999999