softwareheritage=> select convert_from(mimetype, 'utf-8') as mimetype, count(*) as count from content_language cl inner join content_mimetype using(id) where lang='unknown' group by mimetype order by count desc;
           mimetype            | count
-------------------------------+--------
 text/plain                    | 491510
 text/x-ruby                   |  93716
 text/x-c                      |  33233
 text/x-c++                    |  19323
 text/x-python                 |  13690
 text/x-diff                   |   3827
 text/x-lisp                   |   1847
 text/html                     |   1843
 text/x-msdos-batch            |   1629
 text/x-fortran                |    935
 text/x-makefile               |    803
 text/troff                    |    754
 application/zlib              |    443
 text/x-asm                    |    354
 application/javascript        |    346
 text/x-pascal                 |    291
 text/x-tex                    |    209
 text/x-po                     |    154
 text/x-php                    |    141
 text/x-m4                     |    139
 application/xml               |     71
 text/rtf                      |     65
 text/x-shellscript            |     61
 application/pgp-keys          |     44
 text/x-lua                    |     42
 message/news                  |     32
 image/x-portable-pixmap       |     31
 application/pgp-signature     |     29
 message/rfc822                |     27
 text/x-awk                    |     19
 application/vnd.ms-fontobject |     11
 application/x-elc             |      6
 image/x-portable-greymap      |      5
 image/x-xpmi                  |      4
 application/pdf               |      4
 application/x-bzip2           |      3
 application/x-freemind        |      3
 image/x-portable-bitmap       |      2
 text/x-perl                   |      2
 image/gif                     |      2
 model/vrml                    |      1
 text/x-vcard                  |      1
 application/pgp               |      1
 audio/mpeg                    |      1
 application/vnd.ms-opentype   |      1
 text/x-nawk                   |      1
 application/x-archive         |      1
(47 rows)