@property<EOL><INDENT>def per_file_type_data(self):<DEDENT>
ret = {}<EOL>for cache_date in self.cache_dates:<EOL><INDENT>data = self._cache_get(cache_date)<EOL>if len(data['<STR_LIT>']) == <NUM_LIT:0>:<EOL><INDENT>data['<STR_LIT>'] = {'<STR_LIT>': <NUM_LIT:0>}<EOL><DEDENT>ret[cache_date] = data['<STR_LIT>']<EOL><DEDENT>return ret<EOL>
Return download data by file type.

:return: dict of cache data; keys are datetime objects, values are
  dict of file type (str) to count (int)
:rtype: dict