How many dates were recorder administered when poll were sourced from Strategic Vision  and the Republican Jack Hoogendyk had 29%?
CREATE TABLE "opinion_polling_for_the_united_states_se" (
  "poll_source" text,
  "dates_administered" text,
  "democrat_carl_levin" text,
  "republican_jack_hoogendyk" text,
  "lead_margin" real
);
SELECT COUNT("dates_administered") FROM "opinion_polling_for_the_united_states_se" WHERE "poll_source"='Strategic Vision' AND "republican_jack_hoogendyk"='29%';