The goal of this paper is to examine experimental progress in laser wakefield acceleration over the past decade (2004β2014), and to use trends in the data tounderst and some of the important physical processes. By examining a set of over 50 experiments, various trends concerning the relationship between plasma density, accelerator length, laser power and the final electron beam energy are revealed. The data suggest that current experiments are limited by dephasing and that current experiments typically require some pulse evolution to reach the trapping threshold