To obtain a statistical model of future growth that adjusts for two factors; incomplete catching up and continued economic growth in high income countries, Prof. Sachs discusses a “simple rule of thumb” for finding an average converging growth rate. If the United States has an income level of $50,000 per person per year and a growth rate of 1% per annum in person terms, then a country with an income level of $12,500 per person per year is approximately growing ______.