MMR Scale for all divisions in Season 9

So since the new season implemented a new division, I've been concerned a bit about the MMR breakdown for all the divisions. For example, lets say 1500 MMR was Gold 5 for season 8. Since we have a new tier (IRON) does that mean 1500 MMR will be for a lower division or does the MMR stay constant as it was in Season 8?

If anyone knows how the MMR scales for every division please answer my question, Thank you in advance!

Challenger - Grandmaster - Master - Diamond 1 - Diamond 2 - Diamond 3 - Diamond 4 - Platinum 1 - Platinum 2 - Platinum 3 - Platinum 4 - Gold 1 - Gold 2 - Gold 3 - Gold 4 - Silver 1 - Silver 2 - Silver 3 - Silver 4 - Bronze 1 - Bronze 2 - Bronze 3 - Bronze 4 - Iron 1 - Iron 2 - Iron 3 - Iron 4 -