Perhaps you should try some spelling variations:
decrease ratio » decreased ratio (Expand search), decrease at (Expand search), decreased rate (Expand search)
ratio decrease » rate decrease (Expand search), brazil decrease (Expand search), to decrease (Expand search)
decrease their » decrease the (Expand search), increase their (Expand search), decreases the (Expand search)
their patency » the patency (Expand search), their agency (Expand search), their patients (Expand search)
decrease can » decrease in (Expand search), decrease and (Expand search), decrease at (Expand search)
can decrease » and decrease (Expand search), can increase (Expand search), to decrease (Expand search)
decrease or » decrease of (Expand search), decrease on (Expand search), decrease pro (Expand search)
or decrease » not decrease (Expand search), to decrease (Expand search), _ decrease (Expand search)

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( decrease can decrease OR decrease ) OR ( decrease ratio decrease their patency ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease can decrease or decrease ) OR ( decrease ratio decrease their patency ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease can decrease or decrease ) OR ( decrease ratio decrease their patency ))*.