Known collectively as the Crime Index, eight offenses are used to gauge fluctuations in the overall volume and rate of crime: murder and nonnegligent manslaughter, forcible rape, robbery, aggravated assault, burglary, larceny-theft, motor vehicle theft, and arson. The UCR found that nationwide in 1988 the murder volume increased three percent; forcible rape volume increased two percent; upward trends in robbery were evident throughout all population groups; aggravated assault increased six percent with increases in the Northeastern and Midwestern States; burglary volume decreased one percent with cities registering the only increase; larceny-thefts increased three percent and two percent in all cities collectively; motor vehicle thefts increased 11 percent; and arson offenses increased one percent with an increase in cities. 75 tables and appendix.