Complex sentence: In 2009 FpU set a new membership record of 3031 members, this number dipped to 2892 in 2010, however in the aftermath if the 2011 Norway attacks all political youth-organizations reported an up-swing in new members.
Split into simpler sentences: In 2009 FpU set a new membership record of 3031 members; this number dipped to 2892 in 2010. Nevertheless, in the aftermath of the 2011 Norway attacks, all political youth-organizations experienced an upsurge in new members.