Bob Blumberg doesn't need a committee of economists to figure out how the economy is doing. He simply looks at his company's monthly sales figures. Excelsior Legal has been selling bankruptcy forms to lawyers since the 1930s, and lately business has been brisk. Sales of the forms rose more than 20% from 1989 to 1990, he reports. And relief is nowhere in sight: sales for January 1991 were up a staggering 46% over 1990.