Since your specific Bengali request has already been covered, I’ll address the more generic request stated in the first part of your post.

Here you can see the Merit/Post for all local boards (those that do have a local board, but not those that have a single language thread instead), aside from other conventional boards:
https://public.tableau.com/views/BitcointalkMeritDashboard/MeritperPost?:language=es&:display_count=y&:origin=viz_share_link
https://public.tableau.com/views/BitcointalkMeritDashboard/MeritperPostIIChart?:language=es&:display_count=y&:origin=viz_share_link

Fine, that gives us some numbers, which are interesting per se, and allow for the comparison between boards. Unfortunately, they can be somehow indicative of a lack or a low merit distribution, but they cannot speak of the reasons, and the reasons are precisely what gives context to the numbers.

For example, the numbers there do not necessarily display:

-   The degree of interest/quality that the posts actually raise.
-   Whether the merits given “correspond” to that degree.
-   Whether the merits been awarded are concentrated from a Sender/Receiver point of view.
-   How many posts go unmerited when they should opt to being merited.
-   And so forth.

That’s to say, there are some numerical dimensions that can help find undermerited boards, but it’s the qualitive angle that can certify whether the numbers are showing anything meaningful. Undermerited boards should, in my opinion, always shout out by listing multiple un/under merited posts, and drawing attention to a hopfully long list that supports the case.