Question:
Which political party did Ene Ergma belong to in Jan, 2006?

Context:
 Ene Ergma is a member of the Isamaa from Jan, 2006 to Jun, 2016. 
 Ene Ergma is a member of the Res Publica Party from Jan, 2002 to Jan, 2006. 
 Ene Ergma is a member of the Estonian Reform Party from Jan, 2017 to Dec, 2022.

Answer:
Isamaa