While in 1993 US life expectancy statistics revealed a one-year drop from the previous year, the last consecutive two-year fall was between 1962-63, according to the Economist.
The last three-year US population drop statistic was recorded during the 1918-1920 global flu pandemic, which killed an estimated 100 million worldwide.
US population statistics suggest that the trend is a result, in part, of a massive and ongoing epidemic of pharmaceutical opioid addiction in the country, which in 2016 contributed significantly to a minimum of 63,000 drug overdose deaths recorded in the US alone.
An estimated two-thirds of the 2016 US overdose fatalities were caused by patented prescription opioid drugs manufactured by multinational corporations and sold by health care companies including fentanyl, oxycontin and tramadol.
The CDC report documented heart disease and cancer as the two leading causes of death for Americans, while noting the "unintentional injuries" category that includes drug overdoses as arriving in third place, up from fourth place in 2015, and fifth place in 2012, cited by Economist.com.
The report showed that the sharpest mortality gain was made among Americans between the ages of 25-34, where deaths per 100,000 by any cause shot up 11 percent from 2015-2016. Alarmingly, drug overdose deaths in that age group rapidly rose an eye-opening 50 percent between 2014-2016.
If the mortality trend continues, the US is on track to match life expectancy rates in countries like Turkey or Costa Rica, dropping well behind those of developed European nations including the UK, France and Germany.