Yes you can split the catalog easily.
Theres a couple ways you can do this.
1. Duplicate the catalog and previews files on your hard drive to a new location. Rename the files accordingly "2015...." (Your choice)
open the original catalog and select all the images you don't want in it and remove them from the catalog with the delete key- be sure to select remove.
Open the duplicate catalog files and remove the images (the opposite selection from the original catalog) in the same manner.
OR
2. in the original catalog, select the files you want in a new catalog then from the file menu choose export as catalog. Uncheck "include negative files" or you will duplicate the number of images on your drive.
Choose a a location and name for the catalog.
THen em remove the same files from the original catalog in the same manner as above - making sure you select "remove"