I did a community search and could not find an idea on this topic.
It would be nice to see Training > My Activities > Sport - Summarize distance, time, elevation by year and overall. If that would be too much effort how about allowing and export of the data to Excel or CSV so we can import it into our own spreadsheet.
For the large number of walks I did it would be a challenge to add up all the times and distances by hand. There for it would be nice to see a summary by year.