The 21st century hasn’t been easy for yield-hungry Bristol-Myers Squibb (NYSE: BMY) shareholders. The company froze its quarterly payout at $0.28 from 2001 through 2007, and the last four payments of $0.38 constitute a dismal growth rate of about 2.65% over the past 16 years. Despite such cautious raises, the dividend is teetering on the edge of sustainability.