CREATE TABLE member (Member_ID INT, Member_Name TEXT, Party_ID TEXT, In_office TEXT)
CREATE TABLE region (Region_ID INT, Region_name TEXT, Date TEXT, Label TEXT, Format TEXT, Catalogue TEXT)
CREATE TABLE party_events (Event_ID INT, Event_Name TEXT, Party_ID INT, Member_in_charge_ID INT)
CREATE TABLE party (Party_ID INT, Minister TEXT, Took_office TEXT, Left_office TEXT, Region_ID INT, Party_name TEXT)

How many parties of the time they left office, binning the left office time into Year interval, and then split by the minister's name.
SELECT Left_office, COUNT(Left_office) FROM party GROUP BY Minister
SELECT "Left_office", COUNT("Left_office") FROM "party" GROUP BY "Minister"