Perhaps you should try some spelling variations:
"5 ppm decrease" » "5 _ decrease" (Expand Search), "5 pa decreased" (Expand Search), "5 026 decrease" (Expand Search)
"_ non decrease" » "_ point decrease" (Expand Search), "_ note decreased" (Expand Search), "_ fold decrease" (Expand Search)
"5 nn decrease" » "5 _ decrease" (Expand Search), "5 mean decrease" (Expand Search), "5 gy decreased" (Expand Search), "5 non decrease" (Expand Search), "59 nn decrease" (Expand Search), "5 nm decrease" (Expand Search)
"5 a decrease" » "5 _ decrease" (Expand Search), "5 _ decreased" (Expand Search), "5 _ decreases" (Expand Search)

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("5 ppm decrease") OR ("5 a decrease"))) OR ((("5 nn decrease") OR ("_ non decrease"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"5 ppm decrease\") OR (\"5 a decrease\"))) OR (((\"5 nn decrease\") OR (\"_ non decrease\"))))".
• Removing quotes may allow a broader search: (((( 5 ppm decrease ) OR ( 5 a decrease ))) OR ((( 5 nn decrease ) OR ( _ non decrease )))).
• Adding a wildcard symbol may retrieve word variants: (((("5 ppm decrease") OR ("5 a decrease"))) OR ((("5 nn decrease") OR ("_ non decrease"))))*.