A balanced budget was achieved in 2003 and the country began running a surplus the following year. Expenditures amounted to $21.15 billion and revenues were $21.67 billion in 2017. Most government spending on institutions is earmarked for security. The ministries of defence, the interior and justice are allocated the largest share of the annual government budget, whereas those responsible for the environment, tourism and energy receive the least amount of funding. Taxes form the bulk of government revenue at 30% of GDP. Bulgaria has some of the lowest corporate income tax rates in the EU at a flat 10% rate. The tax system is two-tier. Value added tax, excise duties, corporate and personal income tax are national, whereas real estate, inheritance, and vehicle taxes are levied by local authorities. Strong economic performance in the early 2000s reduced government debt from 79.6% in 1998 to 14.1% in 2008. It has since increased to 28.7% of GDP by 2016, but remains the third lowest in the EU.