CREATE TABLE Services (Service_ID INT, Service_Type_Code CHAR)
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 Participants_in_Events (Event_ID INT, Participant_ID INT)

How many events have each participants attended? List the participant id and the number with a scatter chart.
SELECT T1.Participant_ID, COUNT(*) FROM Participants AS T1 JOIN Participants_in_Events AS T2 ON T1.Participant_ID = T2.Participant_ID GROUP BY T1.Participant_ID
SELECT "T1"."Participant_ID", COUNT(*) FROM "Participants" AS "T1" JOIN "Participants_in_Events" AS "T2" ON "T1"."Participant_ID" = "T2"."Participant_ID" GROUP BY "T1"."Participant_ID"