Show years in rating graph of user profile

[germanicianus]

Currently no years are shown on the x-axis of the rating graph in the user profile. This makes it hard to read if a user has a history of more than a year:

I am aware of 3 possibilities to solve this:

1. Add the year to the x-axis-labels. This would be a waste of space:
   
2. Introduce auto-format of the tick labels like this.
3. Show data points in the graph and add tooltips to them like this.

[JeroenDeDauw]

I second this. After playing several years the graph looks really silly:

Just showing the first date (with year!) and the last one would already be an improvement.