I have a table that is exposed to large inserts and deletes on a regular basis (and because of this there are large gaps in the number sequence of the primary id column). It
If we inserted 1 hundred thousand (100,000) records per second into the table then it would take 2,924,712 yrs
If we inserted 1 million (1,000,000) records per second into the table then it would take 292,471 yrs
If we inserted 10 million (10,000,000) records per second into the table then it would take 29,247 yrs
If we inserted 100 million records per second into the table then it would take 2,925 yrs
If we inserted 1000 million records per second into the table then it would take 292 yrs
So don't worry about it