Just talked to a lawyer who used to do copyrights last Sunday. He said technically anything you put in writing that is yours is copyrighted under the law. But, to have legal recourse, you must prove it. That statement on a page may help deter some theft, but the only way to get it absolutely protected is by paying for it to be registered.
I don't think it matters what year. The year it was made and published would be logical to me.