What is the stamp duty reserve tax when the percentage over total tax revenue is 0.79?
CREATE TABLE "revenues_from_stamp_duties" (
  "year" text,
  "stamp_duty_reserve_tax" text,
  "standard_stamp_duty" text,
  "standard_duties_total_revenue_in_million" real,
  "over_total_tax_revenue_in_pct" text,
  "over_gdp_in_pct" text
);
SELECT "stamp_duty_reserve_tax" FROM "revenues_from_stamp_duties" WHERE "over_total_tax_revenue_in_pct"='0.79';