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)
CREATE TABLE Participants (Participant_ID INT, Participant_Type_Code CHAR, Participant_Details VARCHAR)

How many events have each participants attended? Show their average number by each participant type code using a bar chart.
SELECT T1.Participant_Type_Code, AVG(COUNT(*)) FROM Participants AS T1 JOIN Participants_in_Events AS T2 ON T1.Participant_ID = T2.Participant_ID GROUP BY T1.Participant_Type_Code
SELECT "T1"."Participant_Type_Code", AVG(COUNT(*)) FROM "Participants" AS "T1" JOIN "Participants_in_Events" AS "T2" ON "T1"."Participant_ID" = "T2"."Participant_ID" GROUP BY "T1"."Participant_Type_Code"