CREATE TABLE party_host (Party_ID NUMBER, Host_ID NUMBER, Is_Main_in_Charge BOOLEAN)
CREATE TABLE host (Host_ID NUMBER, Name CLOB, Nationality CLOB, Age CLOB)
CREATE TABLE party (Party_ID NUMBER, Party_Theme CLOB, Location CLOB, First_year CLOB, Last_year CLOB, Number_of_hosts NUMBER)

Bar chart x axis nationality y axis the total number, rank in desc by the x axis.
SELECT Nationality, COUNT(*) FROM host GROUP BY Nationality ORDER BY Nationality DESC
SELECT "Nationality", COUNT(*) FROM "host" GROUP BY "Nationality" ORDER BY "Nationality" DESC