Updated

A U.S. Secret Service training document that details 91 breaches reveals security breakdowns dating back to 1980.  The 2003 report, which was obtained by the Washington Post,  shows multiple security lapses involving White House grounds and the protection of the President.

Secret Service spokesman Edwin Donovan tells Fox News the agency has made major changes and improvements in procedures since 1980.  The Secret Service uses past incidents as case studies.  "This document reflects a proactive attempt to evaluate our security and obviously raises the awareness of uniformed division officers and agents about their jobs," spokesman Edwin Donovan said. "We have to be concerned about the threats to our protectees at all times, whether at the White House or away from the White House."

The report illustrates other security breaches such as a small airplane crashing on White House grounds in the fall of 1994.  More serious threats include a live grenade being thrown into the crowd during a speech by then President George W. Bush at a large outdoor venue in Tbilisi, Georgia in May 2005.  The grenade failed to go off but was 100 feet from the President .  One of the more embarrassing breaches occurred back in 1982 when a family of four drove their minivan onto White House grounds.   Officers at the gate assumed the family had clearance and opened the gates after the driver honked the vehicle horn for entry.

The spokesman also points out that other than the State Dinner party-crashers, Tareq and Michaela Salahi, there has been one incident at the White House since 2001.

White House Correspondent Mike Emanuel contributed to this report.