It is a line chart that shows the Refinancing Index from 1991 through 2001 and the percentage of the dollar value of mortgages underwritten with an adjustable rate. The seasonally-adjusted refinancing index, which equaled 100 in March 1990, shows a few spikes, or "waves." The first, in 1993, exceeded 1,000, the next, in 1998, nearly reached 2,500, and the last, in 2001, achieved a record height in excess of 4,000. After each wave crested (except the latest, for which data are not yet available), the refinancing index fell back sharply. In 1994, after the first refinancing wave fell back, 41 percent of mortgages were ARMs, up from less than 20 percent in 1993; in 2000, roughly 50 percent were ARMs, but this dropped to 20 percent during the 2001 refinancing wave.