I'm writing a story about an alternate timeline wherein the bubonic plague never appeared. I was trying to figure out what the population of Europe (the area of the world most affected by the plague) would be had its population not been decimated. I've seen a lot of estimates of total deaths in Europe ranging from 75 million to 200 million. I have a solid math background so I tried to figure this out using the logistic equation, but I quickly realized I was over my head when I started reading papers trying to figure out what the carrying capacity of Europe in the 14th century was. 

I stumbled upon some info that said that it took 200 years for the population of Europe to reach its pre-bubonic plague levels. I then reasoned that if I wanted to find out what the population of the world would be in the current day, I could just look at what the world population would be in 2200 (the year 2018 + 200 is approximately 2200). The number I found was 18 billion *for the world*. You'll recall that I want the population for Europe. 

I am aware of the limitations of population growth models for the far future. Despite this, I'm still really curious about how this question can be answered. Thanks in advance, folks.