The United States lost 309 troops this year in Afghanistan. This is the least number of troops lost there in any of Obama’s four years in office. However it’s almost exactly double the number troops lost there in Bush’s worst year in office: 155 troops in 2008.
All in all the US lost 1,543 troops in Afghanistan in the four years of Obama, and 630 during the seven years that Bush ran the war.
But of course… Obama is ending the war in Afghanistan.