Table 1. The percentage of published articles divided into focus areas from 1997 to 2014.

Focus Areas	1997–1999	2000–2002	2003–2005	2006–2008	2009–2011	2012–2014	All Years
Methodology	0%	0%	13%	10%	17%	18%	17%
Validation	0%	0%	0%	2%	6%	3%	3%
Motivation / Benefits	0%	0%	0%	0%	3%	4%	3%
Projects	33%	43%	54%	46%	41%	49%	47%
General	67%	57%	33%	42%	33%	26%	29%