How do countries measure growth?
The most common way countries measure growth is through GDP. GDP is an acronym for 'gross domestic product.' Gross domestic product is the logical extension of measuring economic growth in terms of monetary expenditures - i.e. how much does a country spend? If a statistician wants to understand the productive output of the steel industry, for example, he needs only to track the dollar or pound value of all of the steel that entered the market during a specific period. Combine the outputs of all industries, measured in terms of dollars/pounds spent or invested, and you get total production. So the simplest explanation is the percentage of difference in GDP between one year & the next - this gives you a growth measurement in GDP.