Structural Efficiency Card building

For this project we had to design and build a card structure.  It needed to be at least 7 and a half inches tall and be able to hold up 5 pounds.  We came in second holding up 5407 grams and had an efficiency rating of 215.  In our original structure we only had an efficiency rating of 40.87.  So for our design renovations we change the whole design.  Instead of triangles we used a circle with cards inbetween for support. 
5407 / 25.1 = 215