Perhaps you should try some spelling variations:
"5 nn decrease" » "k nn decrease" (Expand Search), "_ nn decrease" (Expand Search), "5 nn decreased" (Expand Search), "5 nn increase" (Expand Search)
"10 a decrease" » "19 a decrease" (Expand Search), "1 a decrease" (Expand Search), "10 a decreased" (Expand Search), "10 a increase" (Expand Search)
"5 _ decrease" » "5 _ decreased" (Expand Search), "5 _ increase" (Expand Search)
"50 mean decrease" » "50 mean decreased" (Expand Search), "50 mean increase" (Expand Search)

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"5 _ decrease\") OR (\"5 nn decrease\"))) OR (((\"50 mean decrease\") OR (\"10 a decrease\"))))~".
• Removing quotes may allow a broader search: (((( 5 _ decrease ) OR ( 5 nn decrease ))) OR ((( 50 mean decrease ) OR ( 10 a decrease ))))~.
• Adding a wildcard symbol may retrieve word variants: (((("5 _ decrease") OR ("5 nn decrease"))) OR ((("50 mean decrease") OR ("10 a decrease"))))*.