English usage. Barplot of the number of people/persons in/by/on/per/for

Hello.

What’s the proper way to say in English I want to explain the results of a barplot (with / of / from) the… ?

… number of ( people / persons ) ( **by / per / as a function of / according to ** ) the number of heart attacks suffered.

or also

… number of occurrences ( by / for each / per ) category or year.

What options would you choose?

I know this is not an English grammar forum but I have a question related with plots and statistics and maybe you can help on the Offtopic section.
When I ask this kind of things at language web sites they say they don’t understand what I mean or they just don’t reply. For example I once asked at english.stackexchange.com what is the right option:

  • every/all person’s/people’s time.
  • the time of/from each person.
    but nobody answered.

Could you show the plot you’re talking about?

For example this one:

I have two baplots

  1. x-axis = different categories, y-axis = number of occurrences.
  2. x-axis = total number of occurrences, y-axis = number of people that suffered them.

And persons or people?

as axis labels “number of people” x “number of heart attacks”
or “persons” x “heart attacks per person”

if you like

Then isn’t it right “Number of occurrences by event type”?

Then I should use people for the plural and for the singular is better to say person and each person, isn’t it?

yes

“Number of occurrences by type of event”
“Occurences per Event Type”