PRS-T1 Moving books from one collection to another

[Berzelius]

I have a number of books sorted by year and month. To do this I have created a number of collections with the general format <Year> <Month Number>, for example 2015 07 for July 2015. I wish to consolidate things by having only yearly collections so that, for example, all the books in the twelve 2015 monthly collections would be moved to a new, single collection named 2015.

What is the easiest way to do this? The only way I can see to do this, for example for 2015, is to first make a list of all the titles in 2015 01, go to Collections and open the new, empty 2015 Collection, then got to Books and select and copy all the books in the above list and add them to this new 2015 Collection. I then need to go back to the 2015 01 Collection and delete all the books and then delete the 2015 01 Collection. I then need to repeat the process for the other 11 months in 2015.

As you can see, this would be a pretty cumbersome process. I'm hoping that there is a quicker way. Is there?