http://www.vgchartz.com/article/250163/call-of-duty-a-sales-history/
the article shows that as call of duty keeps going its sells goes up. but as time goes on the buzz isn’t going up by much based off the showing of the graph. based of the last 2 releases being so close in sells. concluding the game hype has not gone up at all.
this chart is interesting because it shows how call of duty sells are on the raise and more and more player are getting the game. and the amount sells have increased by so much.
You need to edit what you have written (perhaps have someone else look it over). Do you have a reference (link)? To me, it looks like as new editions come out, that sales are leveling off, i.e., that the period of highest growth is probably over.
It looks like the growth is slowing down within the last few releases. The slowing of the growth may be due to game quality, but it is impossible to tell without future data. You should work on your grammar.
Did you read the original article? What was the place of the graph in the article?