Comments on the OP suggest it was cover art. Not sure what to make of that without more context. Making it clear the data changed stops it being unethical, but

Comments on the OP suggest it was cover art. Not sure what to make of that without more context. Making it clear the data changed stops it being unethical, but I think the criticism of concatenating two data sources remains. Especially when the point of the graph is the sharp rise at the end - just as the data source changes. You really want to make sure the data sources correlate highly to make that kind of argument.