Task: Question Understanding
Input (English): Passage: In 1915, during World War I, British and South African forces occupied it in the so-called South West Africa Campaign, and SW Africa later became a protectorate of South Africa. On 16 August 2004, 100 years after the war, the German government officially apologized for the atrocities. "We Germans accept our historic and moral responsibility and the guilt incurred by Germans at that time," said Heidemarie Wieczorek-Zeul, Germany's development aid minister. In addition, she admitted that the massacres were equivalent to genocide. Not until 2015 did the German government admit that the massacres were equivalent to genocide and again apologized in 2016. The Herero are suing the German government in a class action lawsuit.
Question: What year did the German government apologize and admit to massacres equal to genocide?
Output (English): date