Correlation Matrix of all Variables.

<p>Note: For full description of variable code, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037515#pone-0037515-t001" target="_blank">Table 1</a>.</p>#<p>Correlation is significant at the 0.01 level (2-tailed).</p>*<p>Correlation is significant at the 0.05 level (2-tailed).</p>$<p>Variables were dropped in the regression model to avoid multicollinearity and for the best fit.