Sioux City Times

Plymouth County residents have a median age of 40-years-old as of 2021, according to US Census Data.

Median ages divide a population into two equally sized groups, rather than the average which takes all the ages of Plymouth County residents and divides it by the number of residents.

OurWorldinData.org, an online project tracking global data and trends, says cities, states, countries and continents with higher median ages typically do better economically and residents earn higher wages than developing countries.

The median age of a United States resident has risen from 29.5-years-old in 1960 to 38.4-years-old in 2019. It has risen fairly consistently by two years every decade since the 1970's.

Ethnicity	Median Age - Male	Median Age - Female
American Indian and Alaska Native	81	46
Asian	-	51
Black or African American	26	34
Hispanic or Latino	23	21
White	40	43
Native Hawaiian and Other Pacific Islander	24	22
Some other race	23	23
Multiracial	18	13