The CITIS team conducted a large scale X-Road central log analysis for service call queries between 2003-2015. This dataset contains over 2 billion service call queries and is a great source to study how usage of e-services has been taken up by the population, what user groups pick services up at what pace, which service are likely to diffuse and how does usage depth and intensity change over the years.
The data is unique as it covers all e-service running on X-Road and allows thus to take a look at the usage of e-governance in Estonia holistically, without having to go to each service owner and combining the data then. The results show a large variance in how e-governance diffuses within the population. The paper summarizing the preliminary findings can be found here.