How are we able to recover our files once deleted from our Recycle bin. If something that is deleted can be retrieved then why the need to delete ? Is it possible to recover files that have been deleted about a year ago (or longer periods) ? Does that mean your Sensitive Data is not safe even after its deletion ?
You can use a simple program like Recuva to recover files. It's pretty reliable if you don't use your computer much afterwards (because then it may be a bit overwritten by normal usage).
After a year, your computer will probably have been used enough to long overwrite it, but it's still possible given time and patience. Erasing from the Recycle Bin isn't secure because it merely marks the space it took on the disk as vacant, but doesn't really delete the data. If you want to securely erase data check out Eraser.