have u looked at a bitcoin calculator
If it wasn't for this I would say with 100% certainty that OP was trolling. There are a lot of calculators in the wild with per year decreases in profitability.
This one even has BFL ads. lol:
http://www.bitcoinx.com/profit/
Default 60% decrease of profitability per year....
It should be 30% profitability reduce per 11 days... Based on 40% difficulty increment...