The number of views is not stored, that is why the users cannot get a chart or overview over time from Stack Exchange. Still: If storing is the problem, why not giving the users themselves the chance to store the views per question on their local drive or in an online "dropbox"?
Of course, everyone can just look up their most important questions and create an Excel sheet or print out a pdf of the question once in a while to have a history of its number of views, but that is manual work.
I suggest an export button that lets you manually export all of your queries together with their views and other information at the current timestamp into a json file or thelike on your local hard disk or into a "dropbox", at best updating the same existing file again and again so that you can extract data over time from just one file.
And in addition one might consider an option in the profile to do this automatically: store the csv after a certain time starting as soon as you visit the site, perhaps the file can also be saved online in a kind of dropbox so that it is not dependent on the computer you are working on. The highest possible storing frequency would be to update the file whenever you access a SO site, the lowest would be to store this once per quarter (or never).
This feature would meet a lot of interest, see the many earlier feature requests:
- Stack Exchange Community Statistics
- Is there a possibility of seeing a graph of a question's views over time?
- Is there any analytics information that moderators can access for individual questions?
- Statistic for views over time --> Only workaround to take the votes timeline
As a bonus to this feature-request, on Stack Exchange, there should be a feature that can load that local file and show the graphs and statistics for all questions saved locally in that file.