I did some research... 18:11 May 7, 2020
This is an interesting one. It does seem to be a regional usage in Chile.
According to the RAE, the definitions of régimen are as follows (I only mention the ones that could apply, due to space restrictions):
"...
2. m. Conjunto de normas por las que se rige una institución, una entidad o una actividad.
...
4. m. Conjunto de características regulares o habituales en el desarrollo de algo. El régimen de lluvias no ha cambiado en los últimos años.
...
5. m. Gram. rección.
..."
Definition no. 2 refers to a set of rules or standards of something, which doesn’t apply too well in the present case.
Definition no. 4 refers to a “pattern” or “index” of something, which doesn’t fit too well in the present context, but it does give an indication that we could be talking about a pattern of GDP growth or the like.
Definition no. 5 seems, oddly enough, the most appropriate here, even though the word relates to a technical term in grammar. The word rección comes from the verb regir, of which one of the definitions is estar vigente (to be current or in force.)
So, after all that, I would say that the suggestion “current GDP” works best. ;-) | 
peer agreement (net): +5