transport, though its agriculture is somewhat dependent on illegal immigrants. According to the California Department of Food and Agriculture, "California agriculture is a $42.6 billion dollar industry that generates at least $100 billion in related economic activity." The state's agricultural sales first exceeded $30 billion in 2004, making it more than twice the size of any other state's agriculture industry. Milk is California's number one farm commodity. The state's almond industry produces the most export value of any farm product, with $4.5 billion in foreign sales in 2016. Dairy and dairy products ranked second to almonds with a total export value of $1.42 billion, a 24 percent increase over 2010. California leads the United States in strawberry production; due to its optimal climate and productive soil, the state is the source of over 80% of the nation's strawberry harvest. Energy Oil drilling has played a significant role in the development of the state. There have been major strikes in the Bakersfield, Long Beach, Los Angeles areas and off the California coast. Solar power in California is also a large employer in the state. There are over 43,000 Californians working in the solar industry, primarily around the San Francisco Bay Area, Los Angeles, San Diego, and the Central Valley. Personal income Per capita income was $58,272 in 2017, ranking 6th in the nation, though with wide variation by geographic region and profession. The highest income counties in California are Marin County and San Francisco County, which both have per capita personal incomes of over $100,000, and are 2 of the top 12 highest-income counties in the United States. Some coastal cities include some of the wealthiest per-capita areas in the U.S., notably in the San Francisco Bay Area and the Greater Los Angeles Area. The most expensive and largest housing markets in the U.S. are in the state of California, so there are a number of communities where average housing prices hover between US$1–2 million. Generally, the Central Valley in northern California is the least expensive area, as is the Inland Empire in Southern California, though prices in these regions are still much more expensive than most other areas of the country, to the point that there are also communities in these areas where housing prices average around the $1 million mark. The agricultural central counties have some of the highest poverty rates in the state. Taxes Taxes are collected by