How True is the Crime Rate Records?

"Year in and year out, the New York Police Department proudly broadcasts its statistics for major crimes. And each year for more than a decade, its numbers have showed how reports of murder, rape, robbery, serious assault and theft have hit historic lows."
Original Article

     The rate of major crimes in New York City is at the lowest it has ever been in recorded history, but the record only accounts for major crimes. Many people who live in New York City also wonder about smaller crimes, such as misdemeanor thefts and assaults. Should the data that the police put out also involve smaller crimes in order for the people to get a more full understanding of the crime rate?