The Eidgenössiches Gebäude- und Wohnungsregister (GWR) is a Switzerland-wide dataset containing detailed information on inhabited buildings and apartments, see OSM-Wiki.
The Switzerland OSM Community told me about the dataset and therefore, i imported it and made a first countrywide evaluation.
In Switzerland, the community have inserted 745.837 Addresses, that is 38.4% of the total of net official 1.941.356 Addresses. The Addresses were counted in OSM at 2018-04-05.
Here, you see the map overview as a screenshot
The map can be used interactively at this link. Zoom in, out and click on a muncipality, to get the results.
The evaluation for switzerland will be updated two times in a week, on Monday and Thurday. I will calculate the evaluation dates and in a few days, you should find them on this page.