Here's the graph: Each one of those bars aggregates 10 years of data. ... There, the data is a little clearer, as the idiosyncrasies of any one year are balanced by its nine compatriots.

The de Bruijn graph B for k = 4 and a two-character alphabet composed of the digits 0 and 1. This graph has an Eulerian cycle because each node has indegree and outdegree equal to2. Following the ...