condition mean min max ZT0-3 5.442681666666666 5.21368 5.572385 ZT4-7 5.91558 5.91558 5.91558 ZT8-11 6.4079049999999995 6.4079049999999995 6.4079049999999995 ZT12-15 5.692629999999999 5.587009999999999 5.7982499999999995 ZT16-19 5.611765 5.611765 5.611765 ZT20-23 6.839880000000001 6.839880000000001 6.839880000000001