What is the year that the issue price (bu) is $26.95?
CREATE TABLE "commemorative_silver_dollar_series" (
  "year" real,
  "theme" text,
  "artist" text,
  "mintage_proof" text,
  "issue_price_proof" text,
  "mintage_bu_clarification_needed" text,
  "issue_price_bu_clarification_needed" text
);
SELECT "year" FROM "commemorative_silver_dollar_series" WHERE "issue_price_bu_clarification_needed"='$26.95';