Scatter Plot from Scientific Research

The average operating hours of high-efficiency generators from 2010 to 2018. The blue hollow circles and red hollow diamonds represent the means of operating hours, conditional on year. The solid green lines are the fitting curves of operating hours, split at a cut point (red dashed line, year 2015). The fitting procedure is carried out in Stata, using quadratic prediction with ordinary least square method. The grey dashed lines indicate the 90% confidence interval.

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