Right!   Dependency ratio: A measure of the portion of a population which is composed of dependents (people who are too young or too old to work).
 
The dependency ratio is equal to the number of individuals aged below 15 or above 64 divided by the number of individuals aged 15 to 64 (workers), expressed as a percentage. A rising dependency ratio is a concern in many countries that are facing an aging population, since it becomes difficult for pension & social security systems to provide for a significantly older, non-working population.
 
In the U.S., the current dependency ratio of 1 dependent person for every 2 workers expressed as a percentage is 50%.
 
Third world countries with a ratio of 1 dependent person for each worker have a dependency ratio of 100%