The table below presents the tax revenue and spending for the government over five years. Government Revenue and Spending Year Tax Revenue (billions of dollars) Spending (billions of dollars) 1 $160 $150 2 130 120 3 150 100 4 120 150 5 100 160 Suppose the government has no debt entering into year 1. At the end of year 5, what is the government's level of debt? Enter your answer as a positive value. $ billion