The image presents a time-series analysis of four different models: Kendall t = 0.58, Kendall t = 0.89, Kendall t = 0.5, and Kendall t = 0.2776e-07. The graphs display the variance and data points over time, with the top graph showing the variance and data points over time, the middle graph showing the variance and data points over time, the bottom graph showing the variance and data points over time, and the bottom right graph showing the variance and data points over time.