Japan GDP at Constant Prices, % change. Units: Percent change. Multiplier: . Estimates begin after 2015 . This data is sourced from www.opendataforafrica.org where it is offered under an open data licence (www.opendataforafrica.org/legal/termsofuse). Annual percentages of constant price GDP are year-on-year changes; the base year is country-specific . Expenditure-based GDP is total final expenditures at purchasers? prices (including the f.o.b. value of exports of goods and services), less the f.o.b. value of imports of goods and services. [SNA 1993] See notes for: Gross domestic product, constant prices (National currency)..