Mazda6 rear vent airflow weak

Hi,

I bought a used 2017 Mazda6 Tourer SE-L NAV D 2.2litre diesel couple of weeks ago (never owned a Mazda before). I noticed that the rear air vents (for the passengers in the back seats) blow the air with much less power than the front air vents. I'd say the air blowing in the back is about 10-20% when on lower air flow settings and maybe 20-30% on the higher air flow settings, comparing to the front air vents. I would expect the air flow to be a bit weaker in the back than in the front but I have no idea how much weaker it should really be.

I would really appreciate if someone can advise on the below questions:

1. How much weaker airflow should be from the rear air vents compared to the front vents?

2. Is there any additional fan/motor in the back to propel the air flow to the rear air vents?

2a. If so where is it located and how to access it?

Thank you