Hello! I'm looking to determine factors that play a role in a country's life span. I want to split the countries up using the percentiles from life expectancy (i.e. 0-25%, 25-50%, 50-75%, and 75-100%). My rationale behind this is to understand how countries with lower life expectancies compare to each other and those with higher life expectancies. Is this statistically valid and, if so, is there a name for this method? If not, is there a more established way to compare countries with low life expectancies to higher ones?