Pollster Accuracy

For reference purposes, I provide the pollsters ranks by accuracy with respect to the national popular vote for President:

CNN: 0.5
Ipsos: 0.5
Pew: 0.7
Rasmussen: 0.7
ARG: 1.5
Research 2000: 1.7
ABC: 2.5
IBD: 2.7
Hotline: 3.7
Gallup: 4.5
Zogby: 4.5
Battleground: 5.7
CBS: 5.7
Fox: 5.7