The World Bank provides open data for many indicators across most countries, spanning the last few decades.
This data is available online with searches available by country codes (iso2c and iso3c), indicator names, and by dates. The indicators can be viewed here. It can also be accessed via an application programming interface (API). The WDI library in R provides access through this API, allowing for easy search and retrieval of data.
Follow the links and have a look.