How many mileposts are there on Anne Street?
CREATE TABLE "table1_10568553_1" (
  "county" text,
  "location" text,
  "street_names" text,
  "milepost" text,
  "roads_intersected" text,
  "notes" text
);
SELECT COUNT("milepost") FROM "table1_10568553_1" WHERE "street_names"='Anne Street';