These word lists are from the SCOWL wordlist set:

downloads.sourceforge.net/wordlist/scowl-7.1.tar.gz wordlist.sourceforge.net/scowl-readme wordlist.sourceforge.net/scowl-7.1-readme

The SCOWL word lists are used primarily for spellchecking.

I use just the 10, 20, and 35 lists by default.

The following information appears in the scowl-readme file linked above.

And here is a count on the number of in each spelling category (american + english spelling category):

Size   Words       Names    Running Total  %
 10    4,427          15        4,442     0.7
 20    8,122           0       12,564     1.9
 35   37,251         224       50,039     7.7
 40    6,802         503       57,344     8.8
 50   24,505      15,455       97,304    14.9
 55    6,555           0      103,859    15.9
 60   13,633         775      118,267    18.1
 70   35,507       7,747      161,521    24.8
 80  143,791      33,293      338,605    51.9
 95  227,056      86,814      652,475   100.0

COPYRIGHT, SOURCES, and CREDITS:

The collective work is Copyright 2000-2011 by Kevin Atkinson as well as any of the copyrights mentioned below:

Copyright 2000-2011 by Kevin Atkinson

Permission to use, copy, modify, distribute and sell these word
lists, the associated scripts, the output created from the scripts,
and its documentation for any purpose is hereby granted without fee,
provided that the above copyright notice appears in all copies and
that both that copyright notice and this permission notice appear in
supporting documentation. Kevin Atkinson makes no representations
about the suitability of this array for any purpose. It is provided
"as is" without express or implied warranty.

Alan Beale <biljir@pobox.com> also deserves special credit as he has, in addition to providing the 12Dicts package and being a major contributor to the ENABLE word list, given me an incredible amount of feedback and created a number of special lists (those found in the Supplement) in order to help improve the overall quality of SCOWL.