Gross fixed capital formation (GFCF), also called "investment", is defined as the acquisition of produced assets (including purchases of second-hand assets), including the production of such assets by producers for their own use, minus disposals. The relevant assets relate to assets that are intended for use in the production of other goods and services for a period of more than a year. The term "produced assets" means that only those assets that come into existence as a result of a production process are included. It therefore does not include, for example, the purchase of land and natural resources. This indicator is available in different measures: GFCF at current prices and current PPPs in US dollars, and annual growth rates of GFCF at constant prices, as well as quarterly data for percentage change over previous period and percentage change over same period last year. All OECD countries compile their data according to the 2008 System of National Accounts (SNA). The indicator at current prices and current PPPs is less suited for comparisons over time, as developments are not only caused by real growth, but also by changes in prices and PPPs.