According to data published by the US Census Bureau, which of the following statements is correct?

a) In recent years, more than 50% of income was earned by the top 20% of people.

b) In recent years, less than 50% of income was earned by the top 20% of people.

c) In recent years, the distribution of income was relatively equal among all income groups.

d) The US Census Bureau has not provided sufficient data to determine the distribution of income among different groups.