The seat of Fresno County, Fresno is the commercial, financial, and cultural center of the San Joaquin Valley and the central California region. The city is the business and transportation hub for four separate agricultural regions in what has been called the agribusiness center of the world. Fresno is also known as the gateway to Yosemite, Kings Canyon, and Sequoia national parks. The city is given an international flavor by a diverse citizenry representing more than 70 nationalities and the largest refugee population in the United States. Over the last two decades, Fresno has been one of the fastest growing cities in the United States. Estimated population had exceeded 450,000 by 2003 and official census numbers revealed a 20.7 percent increase in population between 1990-2000.