The department evaluates English-speaking and French-speaking immigrant applications in the same way and according to the same criteria, regardless of the country of origin. There's no difference in the way applications are processed and in the selection criteria applied by public servants.
I don't know the specific situation of the countries mentioned. Why are there far fewer applicants from Madagascar? I don't know the exact situation in Madagascar, but there may be fewer applicants who qualify for our immigration programs. It's also possible that our immigration programs are less well known in this country. I'm speculating here, but it may be a question of promotion and the ability of applicants to qualify for our immigration programs.