CREATE TABLE Participants (Participant_ID INT, Participant_Type_Code CHAR, Participant_Details VARCHAR)
CREATE TABLE Events (Event_ID INT, Service_ID INT, Event_Details VARCHAR)
CREATE TABLE Services (Service_ID INT, Service_Type_Code CHAR)
CREATE TABLE Participants_in_Events (Event_ID INT, Participant_ID INT)

I want to know the proportion of the total number for each participant type code.
SELECT Participant_Type_Code, COUNT(Participant_Type_Code) FROM Participants GROUP BY Participant_Type_Code
SELECT "Participant_Type_Code", COUNT("Participant_Type_Code") FROM "Participants" GROUP BY "Participant_Type_Code"