The nation experienced a certain shift age distributions over the last decade. With baby boomers moving on to retirement, millennials and Gen Xers began to make up the working population.
To determine where the different demographics are more present, Trulia created a report to see where the youngest and oldest places are in America. The report broke down county demographics into three categories: Young (ages 0-19), working age (ages 20-64) and elderly (65+ years).  After the demographic breakdown, the report compared the population percentages of 2010 and 2017 to show the shift in recent years.
On average, people in the elderly population concentrated towards the South. There was also a significant amount of elderly in the Pacific Northwest and parts of New England.
The youngest generation had the highest population in Utah, rightfully so as they have the highest birth rate.

Cook County

To no one’s surprise, Cook County had the highest working age population. In 2017, the working age in Cook made up 61.4 percent of the population, while 24.4 percent were young and 14.3 percent elderly. Although, despite the highest percentage of working age, Cook did see a high increase in the elderly category from 2010 to 2017. The elderly population in 2010 was 11.9 percent. The working age percentage saw a decrease from 61.6 percent, along with the young group from 26.5 percent in 2010. Cook had a medium home value of $220,000.

DuPage County

For the Chicagoland area, DuPage County had the highest percentage of elders. In 2010, DuPage was 11.6 percent elder, 61.6 percent working age and 27.3 percent young. Seven years later, DuPage had an elderly population of 15 percent, 59.7 percent working age and 25.3 percent young. In 2017, the median home value in DuPage was $289,000.

Lake County

Lake County saw the second highest percentage of elderly in the area at 13.7 percent, an increase from 10.4 percent in 2010. The working age percentage decreased slightly from 59.2 percent in 2010 to 58.8 percent in 2017. The young population also experienced a small from from 30.4 percent in 2010 to 27.5 percent by 2017. Lake County had a $235,500 median home value.

Kane County

Kane County had the highest percentage for the young category at 28.5 percent, although they saw a drop from the 2010 population of 30.4 percent. The working age population for 2017 made up 58.4 percent, while the elderly made up the remaining 13.1 percent. In 2010. The elderly only made up 9.6 percent, while the working made up 58.8 percent. Kane’s median home value was $225,000.

Will County

Will County saw a drop in the young population, but an increase in the working age and elderly demographics. In 2010, the young population was at 31.8 percent, but dropped to 27.9 percent by 2017. The working increased to 59.5 percent, only 0.5 percent higher than 2010. For the elderly, the population increased from 9.3 percent in 2010 to 12.6 percent in 2017.  The median home value was $217,000.