I don't see a baby boom in that curve; just a constant growth of the population.
These guys do, among others. All those long dark nights at home
Two main groups account for the rise in births in Poland. One is the people born during the baby boom of the early 1980s.
This young man got married a year ago when he and his fiancee were 21. Today they are awaiting a baby.
"We have each other, we have jobs to support the two of us, so we can afford a baby. This is natural and we are very happy."
Have a look here too. Quite interesting reading.
This one's interesting. The graph on p. 7 shows the boom in live births between 80 and 85.