Show me the Yen!! How much money do sumo wrestlers make?

I get the question every so often of "How much money do sumo wrestlers make?"  Unfortunately, the real answer is "It Depends."  I know that is pretty unsatisfying, but sumo wrestler salary is confusing and complex.  The top division sumo wrestlers' salaries are made up of the following categories:

1. Monthly base salary
2. Lifetime cumulative record salary, paid 6 times a year
3. Tournament Stipend (To offset expenses)
4. Bout Prize Money (if the bout is sponsored)
5. Tournament Prize Money for winning and individual awards
6. Fan Club Contributions
7. Endorsements

It could be someone's fulltime job trying to keep track of all this and I am sure there is a small army at the Japan Sumo Association doing just that.  However, the majority of a sumo wrestler's salary is typically made up of the monthly salary and this information is published in various forums each year.  I did a quick and dirty Excel Spreadsheet to show the increase in a sumo wrestler's monthly base salary from the early 1970s until last year.  There are some interesting trends:

1. Yokozuna Hakuho with his 40 tournament wins and longevity in the sport yields him close to a $25,000/month base salary.  His true salary is probably 2-4 times that amount.

2. The huge sumo boom that started in the early 1990s and lasted until the late 1990s is reflected in the above pay chart.  Wakanohana, Takanohana, and Akebono all contributed to this huge increase in popularity.

3. The stagnation of the salaries is evident in the 21st century.  Popularity stalled due to the rise of the Mongolians and the subsequent lose of Japanese interest.  Profits dropped and the Sumo Association could not afford to really increase wrestler salary.

4. It is hard to see, but the gap between Juryo and Yokozuna base salaries is closing.

5. The biggest base salary jump is from Sekiwake/Komusubi to Ozeki.  It makes sense since this is the true delineation point between a good and great wrestler.