Table:
0
A
B
C
D
E
F
1
By-election
Electorate
Date
Incumbent
Reason
Winner
2
1882
Franklin North
9 June
Benjamin Harris
Election declared void
Benjamin Harris
3
1882
Wakanui
16 June
Cathcart Wason
Election declared void
Joseph Ivess
4
1882
Stanmore
11 July
Walter Pilliet
Election declared void
Walter Pilliet
5
1883
Peninsula
22 January
James Seaton
Death
William Larnach
6
1883
Selwyn
6 April
John Hall
Resignation
Edward James Lee
7
1883
Inangahua
14 May
Thomas Shailer Weston
Resignation
Edward Shaw
8
1883
Bruce
29 June
James Rutherford
Death
James McDonald
9
1884
Selwyn
15 February
Edward James Lee
Death
Edward Wakefield
10
1884
Thorndon
13 May
William Levin
Resignation
Alfred Newman
11
1884
Kaiapoi
16 May
Isaac Wilson
Resignation
Edward Richardson

Questions and formulas:
Question: When james rutherford is the incumbent how many dates are there?
Formula: ROWS(UNIQUE(FILTER(C1, D1="James Rutherford")))
Formula2: ROWS(UNIQUE(FILTER(C2:C11, D2:D11="James Rutherford")))
Level: medium
Question: When edward shaw is the winner what is the date?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:F1,F1="Edward Shaw"),3))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:F11,F2:F11="Edward Shaw"),3))
Level: medium
Question: When peninsula is the electorate what is the reason?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:F1,B1="Peninsula"),5))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:F11,B2:B11="Peninsula"),5))
Level: medium
Question: When james seaton is the incumbent what is the reason?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:F1,D1="James Seaton"),5))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:F11,D2:D11="James Seaton"),5))
Level: medium