Question: Hangar-7 is a building in Salzburg, Austria, hosting a collection of historical airplanes, helicopters and Formula One racing cars,Hangar-7 is owned by which Red Bull founder, and an Austrian billionaire businessman? 
Sentence (from "Dietrich Mateschitz"): Mateschitz's net worth, as of 2017 , is estimated to be $15.4 billion.
Relevant evidence: No