What is the field stability of Cyanogen Bromide that has an effectiveness of 9?
CREATE TABLE "list_of_blood_agents" (
  "agent" text,
  "melting_boiling_point" text,
  "effectiveness_as_blood_agent" real,
  "persistence_open_area" real,
  "persistence_enclosed_area" real,
  "field_stability" real,
  "storage_stability" real,
  "toxicity_as_blood_agent" real
);
SELECT COUNT("field_stability") FROM "list_of_blood_agents" WHERE "agent"='cyanogen bromide' AND "effectiveness_as_blood_agent">9;