Did you look at the y axis? The graph labels make it pretty clear

Um, the plot is titled: "PHP Trend (Logarithmic Scale)"[1]... Isn't this clear enough? :)

[1] http://news.netcraft.com/wp-content/uploads/2013/01/php-tren...

The y axis labels are clearly in factors of 10 and the title of graphs says "...(Logarithmic scale)" What more could you want them to do? remove the parens? I was going to say bold the text... but it is already!