Bribes in Mexico

From Excélsior, under the headline "The bribe as national sport: it cost 32 billion pesos in 2010":

The average bribe was 165 pesos and as of three years ago it was 138. In the poorest households, corruption is a regressive tax, because it signifies up to 33 percent of their expenses.

The worst entities in terms of corruption until last year were DF, followed by the State of Mexico, Guerrero, Oaxaca, Hidalgo, Tabasco, Colima, Jalisco and Tlaxcala...

These are the two introductory paragraphs for the story, which make it rather odd. Especially the first sentence; I willfully ignore you, context! Anyway, the most memorable portion of the piece came a few paragraphs later:

The case of Tamaulipas was striking, in which Transparency Mexico could not carry out the surveys regarding 35 government services because upon knocking on the doors of the citizens, they refused to open the door because of the insecurity.

Of course, for all I know the local rep knocked on three doors in a single neighborhood right after a gunfight.