36% of all Supreme Court Justices Lacked Judicial Expereince
FindLaw notes that 40 of the 111 Justices that have served on the Supreme Court of the United States lacked judicial experience prior to ascending to the bench. That equates to 36.03% of all Justices.
This is a a take it for what it is worth kind of factoid, but is interesting nonetheless.
1) Two recent Chief Justices are on the list: William Rehnquist and Earl Warren.
2) The likelihood of picking non-judges clearly has diminished in recent decades. Rehnquist was the last, and he was originally appointed to be an Associate Justice in 1972.