Better way to get user progress?

Basically, Users do "tasks" which the website gives them, they perform them outside the computer on pen & paper. Once they're done or didn't succeed they can move to the next "task".

I want to have a page were a user can view own's progress/performance.

To do exactly that, the naive approach would be a Button. Users can click it once they finish a task. with that info I can update a graph, so for example - a graph of how many tasks they did each day, will be updated once they go to their progress page. Or average tasks/day graph... etc.

The thing is, I don't know if users will do the action of clicking the button. Users probably care less about some side feature like this "progress tracking" which is way secondary to the tasks.

In the end, I want to present some stats for the user. I want to do it even without the user interaction with some button. Any suggestions?