The following is a list of California locations by income. California had a per capita income of $29,906 during the five-year period comprising years 2010 through 2014. About every third county and every third place in California had per capita incomes above the state average. Though somewhat counterintuitive, this implies that counties and places with per capita incomes even slightly exceeding that of the state can be classified as "high income" given the natural division of places into a top third (high), middle third (medium), and lower third (low) when ranked by per capita income. Hence, the upper third of all places in this ranking have a per capita income with a lower bound roughly equal to that of the state, about $30,000. The median place and county in California had a per capita income of roughly $25,000, and the lower third of both types of geographies had per capita incomes with an upper bound of about $20,000. Places and counties with the highest per capita income were concentrated in the San Francisco Bay Area, which has a relatively high cost of living. Those with the lowest per capita incomes were concentrated in the Central Valley, an economy in which agriculture assumes a primary role. Entire state Counties The average population of counties with per capita incomes above the state's was twice as high (921,098) as those with a per capita income below the state average (546,543). Even this difference is minuscule when population density is considered: Counties with a per capita income above that of the state were eight times as dense on average (1,540.2 persons per square mile) than those with per capita income below that of the state (192.1 persons per square mile). Marin County had by far the highest per capita income during that period ($58,004); its per capita income was almost $10,000 higher than San Francisco County, which ranked second in that regard. Of the ten counties in California with the highest per capita income, all but Orange were in Northern California, and all but three are located in the San Francisco Bay Area. Of the three not located there, two are smaller counties located in the Sacramento metropolitan area. Orange County's per capita income ranks last among these ten, and its per capita income is about $5,000 more than that of the state. Seven of the ten counties in California with the lowest per