A question about woodpeckers

Foxhill Barn Bed & Breakfast

While helping to prepare breakfast for our guests yesterday morning I looked out at our bird table and was delighted to see a Great Spotted Woodpecker. I called out to Jan, but in doing so merely managed to scare it off - or maybe my appearance alone at the kitchen window was enough to do the scaring. Jan said that GSWs are quite common. I've only ever seen a Green Woodpecker on our table before. Could anyone tell me which is the more common of the two?