The chart below shows the number of households in the US by their annual income in 2007, 2011 and 2015. Summarize the information by selecting and reporting the main features, and make comparisons where relevant.

The given bar chart illustrates the

number

of families categorized by their yearly earnings in 3 milestones - 2007, 2011 and 2015.

Overall

, it is evident that groups of

households

earning less than 50 000

dollars

showed an initial upward trend from 2007 to 2011 and

then

surged

while

the two categories with the highest income experienced the opposite.

In addition

, the

number

of

households

with an income ranging from 75 000 to under 100 000

dollars

per

year

remained unchanged during the whole period. Regarding families earning less than $ 50,000 a

year

, they both reached a peak in 2011. Specifically, there were approximately 24

million

and 30

million

households

earning less than 25,000

dollars

and from 25,000 to 49,999

dollars

, respectively. In the

last

year

of the period, these two categories both decreased by 1

million

each. Turning to the 3 remaining groups, the

number

of

households

earning from 75 000 to less than 100 000

dollars

yearly was about half of the group earning more than 120 000

dollars

, which were nearly 15

million

and 30

million

in turn. In the next 4 years, they rose slightly and

then

peaked at 15

million

and 33

million

in the final

year

.

Additionally

, the

number

of the group with middle income (ranging from $50 000 to $75 000 each

year

) stayed the same at 21

million

during the 3 milestones.