Just for kicks, I looked up several martial arts related topics on Google Trends. here are some of the results that were especially interesting to me. The blue line is aikido, the red line is judo. It appears that judo maintains a moderate and level trend over time with a single spike in popularity - I guess each four years coincident with the Olympics. Aikido is trending steadily downward in popularity but what is really odd is a surge in interest in aikido during the third quarter of each year (magnified below). What's going on there, I wonder. Anyway,
the orange and green lines in the graph above are UFC and MMA, respectively. UFC appears to have a huge spike in interest around each event as well as a strong upward trend. The green MMA line starts low and surpasses all the others except UFC.