Add end year to series

There are many old threads about this, and the result of all of them seem to be that there is no way of adding an end year to a series without asking the IMDb admins to change each title individually. That is obviously a bad system, because there are far too many to change and most people don't know to ask. When the title is first created, you can add in years. The information that can be added when a title is created should be editable even after the title has been created. This would allow contributors to add the end year, saving the admins a lot of time and improving the accuracy of IMDb's information.

There seems to be some information (for instance in IMDb's help: http://www.imdb.com/help/show_leaf?titlecorrects) that seems to suggest that the end year is determined by the last episode of the series. This is presumably talking about what year to pick as the end year, not saying that the system automatically works out the end year based on the date of the last episode; however, the wording is ambiguous. It can't be the latter, because there's no way of marking an episode as the last episode. Perhaps that would also be a good idea?