Who are the persons who have placed a wreath on Memorial Day on the Tomb of the Unknown Soldier in the last 20 years?

It is customary for the President of the United States to lay a wreath at the Tomb of the Unknown Soldier at Arlington National Cemetery every Memorial Day. However, sometimes scheduling for the President prevents this from happening and his appointed representative takes his place.

In recent history the Presidents who have participated in this ceremony have been:

• Ronald Reagan (1981-1989) - Reagan only participated 4 times during his 8 years in office, once he was recovering from being shot, once he was in Moscow and once he was in Virginia. I don't know where he was the 4th time he missed the event. I believe Vice President George H. W. Bush went there those 4 times instead.

• Bill Clinton (1993-2001) - Clinton was in office for 8 years and participated 8 times.

• George W. Bush (2001-2009) - In 2002 Bush was in France and he sent Deputy Defense Secretary Paul Wolfowitz in his place.

• Barack Obama (2009-?) - In 2012 he sent Vice President Joe Biden because Obama was in Chicago on that day.

George H. W. Bush (1989 - 1993) did not go to the Arlington ceremonies at all during his 4 years as President. I believe Vice President Dan Quayle went instead.