Hello everyone,

I am VERY new to R and can only do the most basic things on there. I am currently working on a project. Unfortunately I cannot contact my supervisor at the moment, so I just wanted to see what I could do on my own until I can meet him again.

About the data:

**My goal is to calculate the prevelance rates** of overweight and obesity in a cohort of school kids in Sweden by year (2000-2005). I have the bmi z-scores. I am now looking for a simple way to calculate the prevalence rates for every year.

My approach was to somehow transform the bmi z-scores into a binary variable (bmi z-scores for obesity being 1, and for overweight 0) and then create prop.tables? Would that work? Is there perhaps a better and more elegant way to calculate prevalence rates?

Thank you so much in advance, I hope you understand what my goal is. English is not my first language, so this wasn't easy for me. Anyway. Thank you and have a wonderful Christmas, if you celebrate it.