I am interested to answer the following question: How does the health spending per capita in 2010 of 5 countries different if they have the same age structure in their population, health index and GDP per capita. The age structure I have are in terms of number of people in each age group. There are two health index - life expectancy and mortality rate at birth. What method can I use to answer this question? I am also thinking of including proportion of people living below poverty.