Is downloadable game size increasing faster than broadband speeds?

Sony UK Managing Director Fergal Gara caused a bit of a to-do in the gaming world when he revealed, via a Eurogamer interview, that the digital download of PS4 launch title Killzone: Shadow Fall was "cracking on for 50GB." That whopper of a file size got us thinking: have game sizes been increasing faster or slower than broadband download speeds in recent years?

That is to say, does a game take more or less time to download, on average, than it did in the recent past? We decided to look at five games per major download platform (Xbox Live Marketplace, PlayStation Network, and Steam) per year to represent the wider state of downloadable game sizes for that year. The results are quite a mixed bag, depending on which platform you're looking at.