Slow decay, or playing around with Inkscape’s path simplification tool. “13” was simplified as part of a text node containing all the numbers from “01” to “13”; the other numbers were then deleted. The same goes for “12”, “11”, and so on down to “01”, which was simplified by itself. As more discontinuous paths are selected, the shape changes more and more radically as the algorithm attempts to beat the entire selection into something smooth.