What is the mean Evaluation number (before April 2009) when the Peak lessons taught was less than 80 and the negative percentage of evaluations was 0.8%?
CREATE TABLE "belt_requirements" (
  "evaluation_average_from_february_2011" real,
  "evaluation_average_from_april_2009" text,
  "evaluation_average_before_april_2009" text,
  "pct_of_negative_evaluations" text,
  "submitting_schedule_on_time" text,
  "punctuality_attendance_issues" text,
  "peak_lessons_taught" real
);
SELECT "evaluation_average_before_april_2009" FROM "belt_requirements" WHERE "peak_lessons_taught"<80 AND "pct_of_negative_evaluations"='0.8%';