Very nicely done!
Do you honestly believe that only one in every 500 people would be considered by Jesus as being a good person, worthy of salvation?
I can hear a JW answer "yes" to this, citing the conversation between Jehovah and Abraham prior to the destruction of Sod′om, Go·mor′rah, Ad′mah, Ze·boi′im and Be′la.
The other thing that caught my eye was the assumed rate of 2.4% growth as a constant, moving into the future. I understand too much data would cloud the point you were making with long term projections, but I wonder if a one-sentence statement on how that growth figure has plummeted over the last several years might impact the overall sense of futility in the JW inclination to be excited about future growth. Just my .02