Which Annual ridership (2008) has a Number of stations larger than 70, and an Annual ridership (1998) smaller than 451,971,849?
CREATE TABLE "m_etropolitan_r_ailway_p_assenger_t_rans" (
  "line" text,
  "operator" text,
  "line_length_kilometres" real,
  "number_of_stations" real,
  "annual_ridership_1998" real,
  "annual_ridership_2008" real
);
SELECT MIN("annual_ridership_2008") FROM "m_etropolitan_r_ailway_p_assenger_t_rans" WHERE "number_of_stations">70 AND "annual_ridership_1998"<'451,971,849';