Fig. 2
From: Summarizing health-related quality of life (HRQOL): development and testing of a one-factor model
HRQOL summary score, BRFSS 2013. Histogram shows the distribution of the HRQOL summary score using BRFSS 2013 data set. Larger value means better quality of HRQOL. The “skewed left” distribution suggests that the majority of the population is healthy in terms of HRQOL