Thanks nugget, I agree completely that there are whole range of factors influencing the percentage of growth for certain countries, which is why I stated Cuba and Malaysia as countries that bucked the general trend. However, surely it can be no coincidence that the overall trend indicates that the higher the internet penetration, the slower the rate of growth.
A good way of finding out for sure would be to do an analysis of historical trends, but contrary to cantleave's suspicions, I don't have the time!!