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The answer is indeed quite obvious. The order of the year lines is first by date and second alphabetically in the comment sector. The difference in order is because of the changing mint mark. The G of Goose quill mark (2010, 2011, 2012) and the C of Cat mark (2013) come before the I of In Sets only and the P of Proof. For 2009 however the S of Scales mark comes after the I and P:
By the way, your picture is about the Belgian 20 cent coins, not about the German ones.