Great Leap Forward killed 15 to 55 million people. Their own people.
China actively involved and supported Khmer Rouge, who killed at least a million Khmers. Three million if you believe Vietnam.
Cultural Revolution caused as much as two million deaths.
2000? Did you try to score Internet point? Mao Zedong, who led China during that tumultuous time, is still untouchable in China. 50 years after his death, 26 years after the arbitrary 2000.