Overall, the number of households earning $100,000 or more increased significantly over the period, while households earning less than $25,000 remained relatively stable. A general upward trend is observed across most income categories.
In 2007, households earning between $25,000 and $49,999 made up the largest group, with around 30 million. This number slightly declined to just over 25 million by 2015. The number of households earning less than $25,000 remained almost constant, fluctuating slightly around 25 million in all three years.
Households in the $50,000–$74,999 and $75,000–$99,999 income brackets showed moderate increases. The former rose from approximately 20 million in 2007 to about 25 million in 2015, while the latter went from about 15 million to nearly 20 million.
The most notable increase occurred in households earning $100,000 or more, which grew significantly from around 20 million in 2007 to over 30 million in 2015, making it the largest group by the end of the period.