Math stagnation nations (Latin America)

As you can see clearly, the (vast) majority of these Latin American & Caribbean countries (except Peru so far) have become flat horizontal without progress at all or even got worse over the past 15 years in PISA math tests.

NOTE:

Notice that these mostly Latin America continental and 1 Caribbean countries have their math poverty ranging typically about 50-90% of the student population (in PISA).
The black dotted horizontal lines are the math poverty cutoff point of about 420 in PISA math (which is equivalent to my definition of the mathe poverty). Below the dotted black horizontal lines are shaded in pink, indicating the math poverty zone.
the 3 steep arrows to the right of each of the chart of the math stagnation nations are the steep math poverty ending if the Ministry/Departments of Education embrace the MMU operations. The size of the arrows depend on the levels of the commitments.