Text and Data Mining valid from 2016-11-04
Received: 21 September 2015
Accepted: 22 September 2016
First Online: 4 November 2016
Change Date: 6 December 2016
Change Type: Update
Change Details: The HTML version of this Article previously published incorrectly included an unintentionally appended footnote to Table 1. This has now been corrected in the HTML; the PDF version of the paper was correct from the time of publication.
: The authors declare no competing financial interests.