density altitude

Recently taking off from an airport in New Mexico with the pressure altitude 8800 ft. I was surprised on the takeoff distance. There is an FAA Koch chart that shows the percent of takeoff distance degradation but my degradation was off the chart! I was flying an RV9A with fixed pitch and normal aspiration. Be careful out there!

What was the OAT?

... and with a modern EFIS the DA is usually right ion the screen...