Which term best describes the increasing level of econ

Gross Domestic Product (GDP) describes the increasing economy best.

The increase or decline in the economy is determined by comparing the economy over a certain period. Economic growth is when the production of goods and services increased when comparing different periods. The factors that contribute to economic increase include increase in capital goods, labor force, technology, etc.  

The economic health of one country is expressed in GDP to determine the market value or total monetary of the country's produced goods and services. Developed countries have a substantial high GDP compared to developing countries while underdeveloped countries have even lower GDP. Therefore, this gives a clear basis of how GDP influence the standing of a country economically.