In what year was the first Kawasaki ninja made?

1984 GPZ900R (development in 1982 - 83) and was the first Kawasaki to be marketed under the Ninja brand name in NA. Prior to that bike, most of Kawasaki standards or sport motorcycles were called GPZ. I have the 1984 900R and it has both the GPZ and Ninja names on different parts of the body.