Initialization IDs in google map

I have problem with Google map when i remove markers markers removing from map but when i check all markers id i find that It still exists. i want to initialization it.

Example: if i creat 100 markers and i check ( get marker) i find 100 id.
I remove all markers and it removine from map card i check ( get marker ) i rind 100 id still exist

I creat 50 markes i check (get markes ) i find 150 started like that (101 102 103…150)

How can i make initialization all IDs