Question: How many times was Jillian Grace the centerfold model?
SQL: SELECT COUNT("Date") FROM "1-1566852-6" WHERE "Centerfold model" = 'Jillian Grace';

Question: What were the interview subjects on those occasions where Bai Ling was the cover model?
SQL: SELECT "Interview subject" FROM "1-1566852-6" WHERE "Cover model" = 'Bai Ling';

Question: How many total interview subjects wererthere when the centerfold model was Tamara Witmer?
SQL: SELECT COUNT("Interview subject") FROM "1-1566852-6" WHERE "Centerfold model" = 'Tamara Witmer';

Question: What's the subject of 20 questions in those issues where Jillian Grace is the centerfold model?
SQL: SELECT "20 Questions" FROM "1-1566852-6" WHERE "Centerfold model" = 'Jillian Grace';

Question: Who were the cover model(s) on the 4-05 issue?
SQL: SELECT "Cover model" FROM "1-1566852-6" WHERE "Date" = '4-05';

Question: Who was on the cover when the 20 questions subject was Scarlett Johansson?
SQL: SELECT "Cover model" FROM "1-1566852-6" WHERE "20 Questions" = 'Scarlett Johansson';