There are really two different app markets. The first involves apps which are themselves a source of revenue. The second involves free apps which are part of some larger business plan. Apple will continue to dominate the former category, at least in the neat future, but Android's massive user base will make it a first consideration in the latter.
None of the tables have a column for Android, which, I guess, means that the author only looked at Apps available in the Android market and checked if other version of the App was also available. I think that it would have made for a fairer comparison if the author had also looked at Apps available from iPhone/BB/Win but not for Android.