@Peter Fransiscus - Peter I was there the same time you were in 2015 and most of them looked new and fresh to me too. But in May 2016, most of the yellow mile markers were gone, lots of graffiti and many of the arrows were broken or missing too.
I don't get the vandalism or someone writing their name on the sign. Who cares that so and so was there or so and so loves so and so ? The pilgrim passport should be enough proof that you were there and it is something you can show your friends at home.
Oh well, I will be back again in 5 weeks and curious to see how they will look when I see them again.