By the numbers: A record high for the Nasdaq Composite for the first time in 15 years

The Nasdaq composite index closed at a record high Thursday for the first time since March 2000. Adjusting for inflation, the index is still below the peak it reached during the height of the dot-com bubble.

Here are some facts and figures to help explain how the Nasdaq got from there to here.

Record high close reached Thursday: 5,056 points.

Previous closing high reached March 10, 2000: 5,048 points.

Previous record high figure, adjusted for inflation: 6,908 points.

The share of technology companies in the index:

2000: 65 percent.

2015: 42 percent.

Number of tech stocks in the Nasdaq:

2000: 1,207

2015: 443

Biggest company in the index

2000: Microsoft ($525 billion)

2015: Apple ($749 billion)

Nasdaq trough reached Oct. 9, 2002: 1,114


Data supplied by Nasdaq, FactSet and Birinyi Associates.