https://www.bloomberg.com/news/articles/2020-03-31/italy-s-mild-flu-season-may-solve-mystery-of-coronavirus-deaths
In the northern cities that have borne the brunt of Italy’s more than 12,000 deaths, overall mortality among people age 65 and over was 6% below a baseline from previous years. In the cities of central and southern Italy, the deaths were 3% below normal.
The study didn’t specify how many fewer deaths there may have been, or by how much the pool of vulnerable people had increased.