It's not ideal to use the (American) books in Google's digitized library as a source for studying an orally transmitted phenomenon like jokes, but it's the best we can do from the armchair. At least a few authors write about the jokes themselves, and popular joke types tend to work their way into mediated culture like movies, TV shows, and books. The graphs below show the prevalence over time for references to "Polack jokes," "screw in a lightbulb" jokes, "dead baby jokes," and "blonde jokes."
Polack jokes began in the late '60s and plateaued through the late '80s, declining afterward. I don't remember hearing any Polack jokes in middle or high school ('92 to '99), though we used to tell these all the time in elementary school (later '80s, perhaps early '90s).
How do you make a one-armed Polack fall off a flagpole?
Lightbulb jokes got going in the early '70s and show an apparent peak in the early 2000s, declining since. The peak in actually telling these jokes is earlier, probably the late '80s or early '90s, judging from this mega-collection put together in 1988. But it became so popular that writers continued to use it in a self-aware, ironic way even after they'd begun declining within oral culture, or as a generic way of saying a certain group is really stupid, without providing an actual punchline. ("They're raising taxes again? Jeez, how many politicians does it take to screw in a lightbulb?")
How many queers does it take to screw in a lightbulb?
Two. One to screw it in and the other to say "Fabulousss!"
Dead baby jokes show the quickest rise and fall, taking off in the later '70s and plummeting by the early '90s. I didn't hear these when they were most popular, probably because schoolchildren couldn't appreciate them. But I vividly remember them from high school, later '90s, when we could get black humor. I think we were in a clear minority by that time, since only a handful of us took part. We could stand around outside telling dead baby jokes for the better part of an hour, off-and-on, a good amount of that time just laughing our asses off, and re-hashing them multiple times until the cathartic effect had run its course...
What's red, bloated, and gets stopped at the Mexican border?
A dead baby stuffed full of coke.
As for blonde jokes, Ngram shows the right timing for the rise -- early '90s -- but shows another case like the lightbulb jokes for what should be their decline. The other graphs show data smoothed over 3 years, while this one shows unsmoothed data from each year, to highlight their initial peak in the mid-'90s, and then taking on a second life as a generic phrase for "sexist behavior" in social commentary, not as jokes themselves, let alone ones told face-to-face. For example, a 2004 NYT article about Augusta National Golf Club refers to "the club's inner circle of big business and blonde jokes."
If you search Google for "blonde jokes," those with dates under the title are all from the second half of the '90s, including the first result which is a Tripod page from 1997. Even by then it was a largely curatorial effort, with one example bearing a clear time-stamp from the mid-'90s:
What do you call a dead blonde in a closet?
The 1995 Hide and Seek World Champion.
The academic field of folklore studies has dried up over the past 20 years, as the oral culture has evaporated. Back in 1987, Alan Dundes wrote an entire book called Cracking Jokes: Studies of Sick Humor Cycles and Stereotypes, using many then-current examples. ("Cycle" here means a type, like "dead baby joke," not a rising/falling time course.) But what would his 21st-century counterpart have to discuss, now that people don't tell jokes anymore?
As I said in the medical slang post, we've been through these ups and downs before, the most recent low point in oral culture being the mid-century. But that was followed by an explosion of face-to-face culture, and there's no reason to think we won't see a mass phenomenon like Polack jokes within the next couple decades, as we start leaving our cocoons and hanging out with each other again.