The Dow Jones industrial average has historically taken an average of about 32 months to jump from one thousand-point mark to the next.
Lately, though, things have been much different.
The Dow hit 18,000 for the first time Tuesday, about six months after its first close above 17,000.
Below is a list and chart of roughly how long, in months, it took the index to make each 1,000-point jump. (Some gaps rounded to the nearest six-month mark).