Question: What is the average total value for Spain?
SQL: SELECT AVG("Total") FROM "2-18894139-4" WHERE "Nation" = 'Spain';

Question: What is the sum of silvers for countries in rank 8 with totals over 3?
SQL: SELECT SUM("Silver") FROM "2-18894139-4" WHERE "Rank" = '8' AND "Total" > 3.0;

Question: What is the average total for countries with under 3 golds and 0 silvers?
SQL: SELECT AVG("Total") FROM "2-18894139-4" WHERE "Gold" < 3.0 AND "Silver" < 0.0;