Some systems provide tax exemption for some types of income.[4] Many systems impose tax at different rates for differing types (e.g., capital gains or salaries) or levels of income (e.g., graduated rates). In the United States, gross income includes all income realized from whatever source but excludes particular tax-exempt items, such as municipal bond interest. In 2010, the United Kingdom and the United States both provided reduced rates of tax for capital gains and dividends.