Is anyone familiar with Anki?

'Ive been deleting and installing a couple of decks for the past few months, and Anki has been creating files backup for each one. Now, a large amount of these decks were disappeared, but the back up files still remains in the backup directory, which increases to about 260 MB. Is it secured to remove these unwanted backup files manually? (I can't see any option for Anki to do it automatically, and Anki doesn't do it automatically)? (I don't see any automatic option in Anki to execute it, and it doesn’t automatically accomplished by Anki).
