What has the social media corporations disclosed in their transparency reports?

There is a growing list of corporations that publish transparency reports. The oldest available data is the dataset from 2009 provided by Google. The amount of data sets increases on a semi-annual basis, the standard update period.
The United Kingdom is the country where government make the most requests. Both quantitatively and per capita, the United Kingdom has far more requests than Denmark and Poland.
When you look at compliance rates the field is more evenly divided, although Poland seems to have slightly lower compliance rates than the others, for example when looking at answers from Google in response to polish government requests.
What the corporations have shown is that over time, authorities are requesting increasing quantities of data, involving more accounts. There is also a slight trend towards increasing compliance with requests, although it is not as uniform and differs from country to country.