How to translate database field values?
Have a look at the Field Translation module, a submodule (i18n_field) of the i18n module. Some more details about it (from the Community documentation):


  ... allows for translation of text associated with a field's settings including the label, help text, default value, and list options. Translation of these field settings can be added through the 'Translate interface' pages (Administration &gt; Configuration &gt; Regional and language &gt; Translate interface).


Especially the "list options" mentioned above seem to be what you're looking for.