How many times is the shot volume (cm3) less than 172.76?
CREATE TABLE "english_gun_classes_c_1800_citation_need" (
  "gun_class_pdr" real,
  "shot_diameter_cm" real,
  "shot_volume_cm_3" real,
  "approx_service_bore_cm" real,
  "mass_of_projectile_kg" real
);
SELECT COUNT("shot_diameter_cm") FROM "english_gun_classes_c_1800_citation_need" WHERE "shot_volume_cm_3"<172.76;