Perhaps you should try some spelling variations:
"50 na decrease" » "50 pa decreased" (Expand Search), "50 la decreased" (Expand Search), "50 _ decrease" (Expand Search), "50 n_ decrease" (Expand Search), "50 n_ decreased" (Expand Search), "50 n_ decreases" (Expand Search), "50 ns decrease" (Expand Search), "50 ng decrease" (Expand Search), "40 na decrease" (Expand Search), "50 nsa decrease" (Expand Search), "50 nga decrease" (Expand Search), "50 μa decrease" (Expand Search)
"50 nn decrease" » "50 _ decrease" (Expand Search), "50 mean decrease" (Expand Search), "50 gy decreased" (Expand Search), "50 n_ decrease" (Expand Search), "50 n_ decreased" (Expand Search), "50 n_ decreases" (Expand Search), "50 ns decrease" (Expand Search), "50 ng decrease" (Expand Search), "59 nn decrease" (Expand Search), "50 nsn decrease" (Expand Search), "50 ngn decrease" (Expand Search), "50 μn decrease" (Expand Search)
"50 n decrease" » "50 _ decrease" (Expand Search), "50 _ decreased" (Expand Search), "50 _ decreases" (Expand Search), "50 ns decrease" (Expand Search), "50 ng decrease" (Expand Search), "50 μ decrease" (Expand Search)
"50 a decrease" » "50 _ decrease" (Expand Search), "50 _ decreased" (Expand Search), "50 _ decreases" (Expand Search), "50 μ decrease" (Expand Search), "50 c decrease" (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: "((\"50 na decrease\") OR (((((\"50 n decrease\") OR (\"50 nn decrease\"))) OR (\"50 a decrease\"))))~".
• Removing quotes may allow a broader search: (( 50 na decrease ) OR ((((( 50 n decrease ) OR ( 50 nn decrease ))) OR ( 50 a decrease ))))~.
• Adding a wildcard symbol may retrieve word variants: (("50 na decrease") OR ((((("50 n decrease") OR ("50 nn decrease"))) OR ("50 a decrease"))))*.