Relationships between rural-urban continuum codes and provider ratios for Florida counties. Rural-urban continuum codes, available for each county and three years (1983, 1993 and 2003), were linearly interpolated for each of the 27 years, and then averaged over the period 1981-2007 (A). A metropolitan county is characterized by a Beale code below 4. The provider ratio denotes the number of primary health providers and urologists per 1,000 habitants averaged at the county-level over 1981-2007 (B). The bottom plot shows how the provider ratio has increased with time for rural and non-rural counties (C).