I may be misreading, but I think you made a major mistake here: Ventilators are used primarily for life support, not for people with respiratory issues.
I.e. lots of people have asthma (repsiratory problem), but an inhaler is more than sufficient for the vast majority.
Just like in a case, you need to make sure you understand the question. Clarify your assumptions about what a ventilator is and who would need it before jumping into the sizing blindly.