Update SAM file

[markdebacker]

We need a SAM file that represents Brazil. This may come from IFPRI: https://www.ifpri.org/country/brazil/#country-datasets

[jdebacker]

Other places to look (though I can't track down a spreadsheet file for either:

1. Morrone (2012)
2. Carneiro and Pedroza (2018)