condition mean min max ZT0-3 18.831321666666668 5.905965 25.63595 ZT4-7 5.24346 5.24346 5.24346 ZT8-11 27.790599999999998 27.790599999999998 27.790599999999998 ZT12-15 17.222855 8.50346 25.942249999999998 ZT16-19 7.491535000000001 7.491535000000001 7.491535000000001 ZT20-23 18.215600000000002 18.215600000000002 18.215600000000002