Table 2.

Correlation of number of trials (if >0) vs each variable

Variable	r	95% CI for r	r2
GDP (in million US $)	0.87	0.79 to 0.92	0.76
Population (in thousands)	0.14	-0.11 to 0.38	0.02
GDP/Capita (US $)	0.31	0.06 to 0.52	0.10
Telephones/per 100 inhabitants	0.30	0.06 to 0.52	0.09