From The Art and Popular Culture Encyclopedia
"99 Luftballons" reached #1 in West Germany in 1983. In 1984, the original German version also peaked at #2 on the American Billboard Hot 100 chart and the English-language version topped the UK Singles Chart. The German version topped the Australian charts for five weeks and the New Zealand charts for one week.
When it made the charts in the United States, most US radio DJs incorrectly assumed that "99 Luftballons" translated to English as "99 Red Balloons" and spoke the number 99 in English, saying "Ninety-nine Luftballoons."