Table:
0
A
B
C
D
E
F
1
Province
Commissioner
Assumed office
Duration
Party
Born
2
Drenthe
Jacques Tichelaar
May 1, 2009
4years, 276days
Labour Party
January 2, 1953 (age61)
3
Flevoland
Leen Verbeek
November 1, 2008
5years, 92days
Labour Party
March 5, 1954 (age59)
4
Fryslân
John Jorritsma
May 16, 2008
5years, 261days
People's Party for Freedom and Democracy
September 16, 1956 (age57)
5
Gelderland
Clemens Cornielje
August 31, 2005
8years, 154days
People’s Party for Freedom and Democracy
June 10, 1958 (age55)
6
Groningen
Max van den Berg
September 1, 2007
6years, 153days
Labour Party
March 22, 1946 (age67)
7
Limburg
Theo Bovens
June 30, 2011
2years, 216days
Christian Democratic Appeal
October 1, 1959 (age54)
8
North Brabant
Wim van de Donk
October 1, 2009
4years, 123days
Christian Democratic Appeal
May 17, 1962 (age51)
9
North Holland
Johan Remkes
July 1, 2010
3years, 215days
People’s Party for Freedom and Democracy
June 15, 1951 (age62)
10
Overijssel
Ank Bijleveld
January 1, 2011
3years, 31days
Christian Democratic Appeal
March 17, 1962 (age51)
11
South Holland
Jan Franssen
May 3, 2000
13years, 274days
People’s Party for Freedom and Democracy
June 11, 1951 (age62)
12
Utrecht
Willibrord van Beek
September 15, 2013
0years, 139days
People’s Party for Freedom and Democracy
January 15, 1949 (age65)
13
Zeeland
Han Polman
March 1, 2013
0years, 337days
Democrats 66
January 16, 1963 (age51)

Questions and formulas:
Question: What is the duration of the commissioner from the zeeland province?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:F1,A1="zeeland"),4))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:F13,A2:A13="zeeland"),4))
Level: medium