Table 1. Factors purported to influence B. burgdorferi seroprevalence.
| Factors and Notation | Data period | Scale |
|---|---|---|
| Annual temperature: Xs,1(t) | 1895–2015 | Climate Division |
| Annual precipitation: Xs,2(t) | 1895–2015 | Climate Division |
| Annual relative humidity: Xs,3(t) | 2006–2015 | Climate Division |
| Elevation: Xs,4(t) | 2012 | County |
| Percentage forest coverage: Xs,5(t) | 2012 | County |
| Percentage surface water coverage: Xs,6(t) | 2010 | County |
| Population density: Xs,7(t) | 2011–2014 | County |
| Median household income: Xs,8(t) | 1997–2014 | County |
Note, Xs,k(t) is used to denote the value of the kth factor in the sth county during the tth year.