how common is lyme disease?

NOT COMMON, its only common because theres a large population out there that believes in chronic lyme(there is a whole industry and cult out there), which is not a real disease, and most likely they have delusional parisitosis, or some mental disorders. if you notice a bull-eyes rash at anytime see a doctor asap.

Extremely common effects about 80% of the population

very

Lyme disease is the most commonly reported vectorborne illness in the United States. In 2015, it was the sixth most common Nationally Notifiable disease. However this disease does not occur nationwide and is concentrated heavily in the northeast and upper Midwest.

A simple Google search would have answered your question.