how many total where last/current driver(s) is narain karthikeyan ( 2010 )
CREATE TABLE "by_nationality" (
  "country" text,
  "total" real,
  "champions" real,
  "current" real,
  "first_driver_s" text,
  "last_current_driver_s" text
);
SELECT COUNT("total") FROM "by_nationality" WHERE "last_current_driver_s"='Narain Karthikeyan ( 2010 )';