There are a number of reasons why data may not be available for some indicators for all countries and years. Some indicators are derived from sporadic surveys and are only available every few years. Some data sets or indicators are only available from the year they were initiated. For example, Doing Business indicators start from 2003 when the program was launched. Government finance statistics uses updated indicator definitions and methodology which only allowed for a consistent time series beginning no earlier than 1990. For the same reason, balance of payments statistics time-series only start in 2005. Some countries do not regularly report data due to conflict, lack of statistical capacity, or other reasons (e.g. Somalia, North Korea, and some Caribbean and Pacific island economies). And some countries do not have data for earlier years simply because they did not exist (e.g. countries of the former Soviet Union, South Sudan, Eritrea, Timor-Leste). These are some general reasons for missing data and we will be happy to answer your questions about specific indicators or countries.