I would like help analysing a dataset on expert opinions about how the prevalence of a historical phenomenon changed over human history. The dataset contains 360 samples with location, time range and prevalence. I'm ignoring location at this stage. Still, these time ranges go from just one year to an entire century. Given I have no formal statistical training whatsoever, I'm unsure how to aggregate these data points. Could I get a quote for that?
Once this is done, I could also use some help with selecting the best coding method for expert opinions. That is, converting something like "over 60%" to a definite percentage range. Currently, I'm coding "over x%" as "x+20%". There are also potential additional stages of this project if anything interesting comes out of this initial analysis. For instance, I would like to add the location and pair that to a historical population dataset I have to get an overall global prevalence over time. At this stage, I might also expand my sample size. Could I get a separate rough quote for these later stages as well?