A data frame with 73 observations on the following 7 variables.
POP
Total population in milions
MOR
Number of infant deaths per thousand births
CAR
Number of motorized vehicles per hundred inhabitants
DR
Number of medical doctors per thousand inhabitants
GNP
Gross national product per inhabitant in thousands of US dollars
DEN
Density in inhabitants per square kilometer
TB
Trade balance, defined as total exports/(total exports + total imports)