For much of the last century, the annual growth rate of energy utilization in the world was 3.5% per year. At present, the rate of global energy usage is approximately 15 TW. When considering only coal, oil, and gas, roughly 74,000 EJ of energy are globally available through fossil fuels. Assuming the 3.5% growth rate continues from now into the future, how long will it take to exhaust these fossil fuels?