The best way to preserve statistical data for the long term is to store both the data and the data documentation in an ASCII format. The Stattransfer software package (https://stattransfer.com) makes it possible to convert data from one software format to another. This software offers the option to convert SPSS files (.sav) and STATA files (.dta) to data and setup (.dat and .sps for SPSS; .dat and .DO for STATA).
.csv (comma separated values) and .txt are also simple text formats that can be used for the storage of statistical data.
If statistical computer programs support text formats for exporting data, they should be used.
Data and setup is a preferred format for file type Statistical data.