In 2011 (latest data) juvenile courts in the United States handled more than 1.2 million delinquency cases that involved juveniles charged with criminal law violations.
From 1985 through 1997, the number of delinquency cases climbed steadily (62%) and then fell 34% from 1997 through 2011.
Juvenile courts handled 7% more cases in 2011 than in 1985. This overall pattern of increase followed by decline is the result of the trends of various offense categories combined.
Public order offense cases increased steadily from 1985 through 2005 (129%) and then declined 28% by 2011.
Person offense cases increased through 1997 (131%), leveled off through the mid-2000s, and then fell 27% between 2005 and 2011.
Drug law violation cases more than doubled between 1985 and 1997 and then gradually declined (20%) through 2011.
Although these patterns differed, each increased through the 2000s, followed by a decline. In contrast, property offenses showed quite a different trend.
Between 1985 and 1995, the number of property offense cases increased 31%. Since 1995, the number of property offense cases declined steadily (down 51% from 1995 through 2011). Thus, property offenses were the one general offense category that declined overall from 1985 through 2011 (down 36%).
Source: http://www.ojjdp.gov/pubs/248409.pdf .