How many pole position achieved 0 points from Mexico?
CREATE TABLE "by_name" (
  "name" text,
  "nation" text,
  "seasons" text,
  "championship_titles" text,
  "races_starts" text,
  "poles" real,
  "wins" real,
  "podiums" real,
  "fastest_laps" real,
  "points" text
);
SELECT COUNT("poles") FROM "by_name" WHERE "points"='0' AND "nation"='Mexico';