1. Less than 5,000 people live here.
[Does 'less than 5,000' include '5,000'?]
2. More than 5,000 people live here.
[In math, does 'more than 5,000' include '5,000'?]
#1 should be “fewer people” instead of “less people.” (“People” is a count noun.) And I’d say it means from 1-4999 people.
#2 seems to mean from 5001 and up.
5,000 doesn’t seem to count for anything, does it? =)