Airport Extreme not working on multiple floors

I recently purchased an Airport Extreme and I am not seeing the performance that I was expecting. On the same floor as my Airport, I am getting 14Mbps down and 14Mbps up. When I go downstairs, I get .5Mbps down and 13Mbps up. I purchased an Airport Express to act as an access point on the first floor of my house but that did not help at all. My house is only 1600 sq. ft. so I know it is not an issue with the location of the Airport.

Any suggestions?