This conversion seems to be related to some transfer of various of editions of tax return files, or at least some of their parts in TurboTax or similar accounting / tax preparation software. Perhaps not a straightforward conversion, but doable in the original software, although data in tax return files are related to a single year only.
Convert TurboTax tax return file to TurboTax tax return 2014.
We found one software available in the database for this conversion.
Microsoft Windows software - convert tax to tax2014 on Windows
A tax preparation software developed by Intuit
Convert from tax file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.