condition mean min max ZT0-3 11.652765 11.652765 11.652765 ZT4-7 9.882600499999999 9.882600499999999 9.882600499999999 ZT8-11 10.5726585 10.5726585 10.5726585 ZT12-15 9.2919315 9.2919315 9.2919315 ZT16-19 9.5656545 9.5656545 9.5656545 ZT20-23 9.577161499999999 9.577161499999999 9.577161499999999