Google Insights for Search puzzlers

I happened upon the Google Insights for Search page this evening. After testing a few search terms and observing patterns in the data, I came up with a little game. It goes like this: pick a trend, and then see if you can find search terms that generate that trend. So for example, suppose you want a trend that consists of a narrow annual spike, like this.

1. Annual, sharp peak.

This trend was generated by using a holiday as the search term. Can you guess which one?

Below are several additional trends. See if you can guess how each was generated, or try generating your own. I’ll post the answers in a couple of days.

2. Annual, broad peak.

3. Peaks twice per year.

4. Peaks four times per year.

5. Peaks every two years.

6. Single broad peak.

7. Steady multi-year rise.

Bonus challenge: Come up with terms that generate a steady multi-year fall.