The USA makes one request per 66726 citizens. France makes one per 61328.6 citizens, Australia one per 63405.5, and the United Kingdom is at one per 54216.9 (The best estimate I found for the population was 63 million; using the figure from census data in 2001, it's one per 50593.1). The absolute number of requests does not give much useful information except when you also take into account the relative populations of countries; using requests per citizens as a metric, the USA is in no way the "snoopiest govt".

Edit: While I haven't gone through these really systematically, I think that Mexico might have the lowest ratio, at one request per 3159742 citizens.