Sure. See here among other places. That includes about $200 billion in immediate costs (including losses to the insurance industry, loss of business, the actual destruction, loss of income, the amount paid to the airline industry, etc.) and about $200 billion additional costs of doing business (increased security, disaster planning, etc.)for each of the last 4 years. Not much, I suppose in an economy of our size but a billion here and a billion there and you're starting to talk about real money.