Mixed portfolio data set - allow change of starting year?

[wasdana]

In the tab "How is it invested?", we can set the starting year for the dataset; we can change it from the default 1871 to another year.

How about allowing a change of starting year also for the "mixed portfolio" datasets? It would be useful if its 1927 default starting year could also be changed by the user.

Thanks for considering my request.