When did the first day logo of the National Geographic Center begin?

Founded in 1987, NGC Coin Appraisal and Rating Company is the world's leading and largest third-party coin rating service organization and the only coin collection institution chartered by the US Congress. Both the American Numismatic Association (ANA) and the Professional Paleontologist Association (PNG) have designated NGC as their official rating service agencies. NGC-grade coins have a globally recognized value and are recognized by major collectors and auction houses in the world.