mnli premise: Two years ago, American Lawyer magazine (a sister publication of the Law Journal) found that during the fat year of 1999, the approximately 50,000 lawyers at the nation's 100 highest-grossing firms spent an average of eight minutes a day on pro bono cases, or about 36 hours per year, which is down significantly from an average 56 annual hours during the recession year of 1992. hypothesis: In 1999, lawyers at the nation's highest grossing firms spent 52 hours per year on pro bono cases.