WASHINGTON, December 14, 2004 - The Army National Guard yesterday said it had given USA TODAY an inaccurate count of the total number of Guard troops in Iraq since the beginning of the war in March 2003, but it still could not provide a precise count.

USA TODAY used the inaccurate Guard numbers to construct an analysis that showed part-time troops from the Army National Guard were more likely to die in Iraq than their counterparts in the active-duty Army.

Without more precise figures, there is no way to accurately compare death rates between various branches of U.S. military forces during the Iraq war.

The Guard said last week that 37,000 Guard troops had set foot in Iraq since the start of the war. Yesterday, Guard spokesman Scott Woodham said 90,972 Guard troops had been ordered to Iraq, but he could not say how many had actually gotten there and how many were in mobilization stations or on their way.

Woodham gave two explanations for the error. In a telephone interview with USA TODAY at midafternoon yesterday, Woodham said the National Guard Bureau made "an internal mistake" in compiling the numbers. He said personnel at Guard headquarters had misread a series of numbers on a spreadsheet and that accounted for the lower figure.

In a second conversation about two hours later, Woodham said he "misunderstood the question" when asked how many Army Guard troops had deployed to Iraq since the beginning of the war.

Yesterday, the active-duty Army also revised one of the numbers it had given USA TODAY. Army spokesman Dov Schwartz said 659 Army soldiers have died in Iraq since the start of the war, up from the 622 the Army cited last week.

Battle deaths for part-time troops from the Army Guard and the Army Reserve - who typically drill just a weekend a month and two weeks in the summer unless there is a war - are still significantly higher than for part-time troops in past conflicts, Woodham said. Throughout the 12-year Vietnam War, for example, fewer than 100 Guard troops were killed, compared with the 145 who have died in less than two years in Iraq.

Army Guard and Army Reserve soldiers are assigned some of the most dangerous missions in Iraq, including convoy duty and guarding facilities.

Part-time troops now make up about 40 percent of the U.S. troops on the ground in Iraq.

Several other military branches told USA TODAY last week that they could not determine how many of their troops had served in Iraq since the war began.

The Marine Corps, Navy and Air Force could not provide troop numbers.