How to get frame rate and stream count information of video files into a text file with using MediaInfo?

I have a problem with a console command executed from within a batch file in a command prompt window on Windows 7. I want to get the frame rate and the number of audio streams of a video and write them into a text file. For the frame rate there is no problem, I run this command from a batch file:

for %%a in (C:\Documents) do (
    echo.
    Mediainfo --Inform=Video;%%FrameRate%% %%a
)>> "D:\TestFrame2.txt"

But for the number of audio streams, it returns an empty text and there is no error message. I use exactly the same batch file, but I replaced Video by Audio and FrameRate by StreamCount.

I see these parameters when I run Mediainfo --Help-Inform.

And also a lot of others options like Mediainfo --Inform=General;%%AudioCount%% don't work.

I have tested already to replace Inform by Output and there is no change. And I have tested also to use this command directly in the console window without redirecting the results into a text file and it's the same thing.

What is the reason for not getting number of audio streams written to the text file?

via Chebli Mohamed