I honestly don't have statistics on that, do you? It would probably be blurred by definition issues anyway. So let's do somelogical analysis on the subject, since at the moment we can't do empirical analysis.
You're point doesn't hold for the following reasons: While it is true that government regulation can
and sometimes has
reinforced monopoly, it is also true that government regulation has the potential to be the best way to destroy monopolies. In contrast, there is absolutely no reason to think that a lack of regulation would reduce monopolies.
I'm a little vexed, because so far, this is one of the most unfounded arguments you have used, and I don't know where it came from. How would a lack of regulation prevent monopoly? The theoretically model of monopoly developing behavior outlines something that could develop out of total anarchy. No regulation is necessary. Human nature and a multitude of people living together is all it takes. We may be talking about business and monopolies here, but this is not a strictly economic model. This applies to political power, and it applies to military power. It's flatly just a power model.
People, without regulation, will seek to dissolve all competition to reap the undoubtable benefits of being an unchallenged power.
Now, if a government had established several policies in favor of monopolies, than monopolies will do even better than in an unregulated environment, duh. Government reinforcement tends to strengthen things. But on the other hand, government, unlike a situation without regulation, can also inact means to directly prevent monopolies from taking place. Government stands as something that can actually stop monopoly.
So in summary:
Government regulation done wrong = monopolies .
Government regulation done right = no monopolies.
Lack of goverment regulation done in any way you can imagine = monopolies.
So it makes more sense to go with government here.