The group's Audit of Anti-Semitic Incidents, published annually since 1979, tracks anti-Jewish acts reported to the ADL and law enforcement agencies. While not a scientific measure of anti-Semitism, last year's audit counted 1,547 incidents in 41 states and the District of Columbia, the lowest number recorded since 1989.
The numbers, however, do not tell the whole story. Last summer, Jews were targeted in shootings and synagogue arsons in Chicago, Sacramento and Los Angeles.
"While the drop in number of anti-Semitic acts over the last five years is in one sense very encouraging; unfortunately, the horrific acts of violence and intimidation we have witnessed in the last year overwhelm the statistics," said Abraham Foxman, the ADL's national director.
The audit broke down anti-Semitic incidents into 868 acts of harassment, down 3 percent from the previous year, and 679 acts of vandalism, down 5 percent. Continuing a nine-year trend, acts of harassment outnumbered those of vandalism.
States with highly concentrated Jewish populations -- including New York, Massachusetts and California -- reported the most incidents, with all three showing increases from the previous year.
The audit referred to the overall decline as a reflection of "the continuation of a downward trend that has resulted in a 25 percent drop in anti-Semitic incidents over the last five years." The ADL partly attributes the decline to improved security measures at high-risk locations like synagogues and Jewish community centers.
Additionally, a significant decline of anti-Semitic acts was noted on college campuses. Sixty incidents were documented, the lowest number reported since 1989 and a 30 percent drop from the previous year.
A growing forum for anti-Semitism not easily combated or tracked, however, is the Internet.
"Extremists and hate groups are using the Internet to spread their anti-Semitic message which can inspire others to violence,'' Foxman said.
Lists of e-mail addresses are increasingly easier to access, making a growing number of people vulnerable to hate mail, said Myrna Shinbaum, a spokeswoman for the ADL. As with print mailings, mass e-mailings of anti-Semitic messages are classified by the audit as one incident, regardless of the number of people who received the message.