When was the term "the Generation X" made up?

W: So what year were you born?   
M: 1971. I’m part of the Generation X.
W: Generation X? I think I’ve heard of it, but I don’t know what it means.
M: It’s basically a trendy classification for the generation born in the United States after 1965. It was coined in 1991 by author Douglas Coupland, who wrote a book by that title.
W: What characterizes the X-generation?
M: Well, they are basically college educated and dissatisfied with their careers.
W: So, they are basically overeducated and underemployed?
M: Right. And they also have a pessimistic attitude about society. They don’t see life getting any better. They don’t even like the label "Generation X".
W: I can see why. Nobody likes to be stereotyped.
M: There are actually two different stereotypes associated with the Generation X-ers. One is the slacker image in which the individual has no motivation. The other extreme is the highly educated computer hacker who has his own business.
W: So tell me some more terms about the Generation X.
M: Sure. There’s another term called “McJob”. It was coined by Coupland and refers to low paying jobs with no prestige and no future.
W: Like working at McDonalds? Is that where they got the "Mc"?
M: Exactly.