Table:
0
A
B
C
D
E
1
Leader
Party
Leader's Seat
Number of Seats
Leader since
2
Peter Robinson
Democratic Unionist Party
Belfast East
38
31 May 2008
3
Raymond McCartney
Sinn Féin
Foyle
29
2011
4
Tom Elliott
Ulster Unionist Party
Fermanagh and South Tyrone
16
22 September 2010
5
Margaret Ritchie
Social Democratic and Labour Party
South Down
14
7 February 2010
6
David Ford
Alliance Party of Northern Ireland
South Antrim
8
2001
7
Steven Agnew
Green Party in Northern Ireland
North Down
1
2010
8
Jim Allister
Traditional Unionist Voice
North Antrim
1
2007

Questions and formulas:
Question: Which leader has been a leader since 2007?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,E1=2007),1))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E8,E2:E8=2007),1))
Level: medium
Question: How many seats does leader Raymond McCartney have?
Formula: SUMIFS(D1,A1,"raymond mccartney")
Formula2: SUMIFS(D2:D8,A2:A8,"raymond mccartney")
Level: easy
Question: Which leader of the Democratic Unionist party has more than 8 seats?
Formula: LET(query1,LET(query1,FILTER(A1:E1,B1="democratic unionist party"),SUMMARIZE(CHOOSECOLS(query1,1),SUMX(CHOOSECOLS(query1,4)))),FILTER(query1,CHOOSECOLS(query1,2)>8))
Formula2: LET(query1,LET(query1,FILTER(A2:E8,B2:B8="democratic unionist party"),SUMMARIZE(CHOOSECOLS(query1,1),SUMX(CHOOSECOLS(query1,4)))),FILTER(query1,CHOOSECOLS(query1,2)>8))
Level: hard