Here’s a neat graph I found. It shows the acceptance rate – not count – of patent applications in the past 30 years.

There are two interesting points here. First, you can see how the dot-com boom and the rise of technical patents confused the US Patent and Trademark Office (USPTO). Thus, you see a pretty big, fluffy explosion of granted patents. Nearly everything submitted was accepted!
But the after the bubble burst and word got out of those retarded patents, it seems the USPTO listened!
Really, what happened was a clamp down on standards. Before, with the huge spike in applications, their emphasis was on being quick. Then, after their reputation got slammed, they decided a back-log of patent applications was better than a surge of bogus patents.
Now patent acceptance rates are very low. Mind you the graph starts at 50%, but even still, it’s a 50% drop from rates 30 years ago.