Quiet casualties within Communist regimes alone killed over 140,000,000 people in the 20th Century.
R. J. Rummel, professor emeritus of political science and a Nobel Peace Prize finalist who has published dozens of books chronicling so-called "democide," or death by government, said the new Chinese figure – nearly double his previous estimate of about 38 million – was based on what he believes was Mao's duplicity in China's great famine of 1958 to 1961......
In all, Rummel estimates about 174 million people were killed during incidents of democide in the 20th century, "of which communist regimes murdered about 148 million," he said, adding, "Communists overall have murdered four times those killed in combat."
Don't expect to hear these numbers in an American university unless you take a class from Rummel himself.
China, Cuba, North Korea, and Vietnam (among others) carry the ignoble Communist tradition into the 21st Century.