The bar chart illustrates the annual income distribution of households in the United States across various income levels in the years 2007, 2011, and 2015.

Overall, a consistent pattern is observed among three years. The smallest number of households fell with the $75,000 - $99,999 income range in 2011, whereas the highest number was recorded for incomes exceeding $100,000 in 2015.

Looking at the chart more closely, households earning less than $25,000 numbered around 25 million in 2007, increasing to 29 million in 2011, and then slightly decreasing to 28 million in 2015. It is notable that the income ($75,000 - $99,999) consistently represented the fewest households, with approximately fewer than 15 million in both 2007 and 2011. However, there was notable surge in households earning over $100,000, reaching almost 35 million in 2015, compared to around 28 million in 2011, which had a significantly growth during this period.

The second highest number of households was in the $25,000 - $49,999 income range, with around 30 million in 2011. The group of $50,000 - $74,999 remained almost 20 million during these years, with a slight fluctuation.