Key numbers related to the Vietnam War and how Vietnam has changed in the 40 years since the fall of Saigon:
—92.5 million: Vietnam's population in 2014. More than two-thirds of the country was born after the war ended.
—More than 1.3 million: Number of Americans of Vietnamese ethnic origin, up from 231,000 in 1980.
—More than 58,000: Number of U.S. servicemen killed in Vietnam and neighboring Laos and Cambodia.
—More than 3 million: Number of Vietnamese communist fighters and civilians killed. That does not include South Vietnamese forces, whose losses are estimated by some American sources at up to 250,000.
—1,971: Number of Americans missing in action or otherwise unaccounted for in Vietnam at war's end.
—More than 700: Number of U.S. remains recovered and identified by joint U.S.-Vietnamese teams since then.
—About $250 billion: Estimated U.S. spending on the war from 1965 to 1975 — the equivalent of more than $1 trillion in today's dollars.
—5 million to 7.8 million: Tons of U.S. bombs dropped on Vietnam.
—800,000: Estimated tonnage of unexploded bombs and land mines left at war's end.
—35,000 to 42,000: Number of people killed by that ordnance since war's end.
—$80 million: Amount U.S. has spent on ordnance cleanup efforts so far.
—12 million: Gallons of the herbicide Agent Orange sprayed by the U.S., over about 10 percent of South Vietnam, from 1961-71. It contained the toxic chemical dioxin and is blamed for cancer, birth defects and other serious health problems among American veterans and generations of Vietnamese.
—2.1 million to 4.8 million: Number of Vietnamese exposed to Agent Orange.
—2.4 million: Estimated number of U.S. service members exposed.
—$65 million: Amount the U.S. has spent cleaning up dioxin in Vietnam so far.
FROM WAR TO BUSINESS:
—$170 million: Vietnam's exports in 1976.
—$132 billion: Vietnam's exports in 2013.
—Less than $500 million: U.S.-Vietnamese trade in 1995, when the countries normalized relations.
—$35 billion: U.S.-Vietnamese trade last year. The U.S. is Vietnam's biggest single-country export market.
—7.6 million: Number of foreign tourists to Vietnam in 2013.