Figure 1
The horizontal axis is labeled “newt” and marked from “2021m12” on the left to “2023m12” on the right. The vertical axis is labeled “C U S U M squared” on the left and is marked 0 at the bottom and 1 at the top on the right axis. The graph shows a red line connecting circular markers. A legend at the top indicates that the line represents “C U S U M squared.” The line begins at 0 and ends at 1. A cyan diagonal line extends upward from the origin, with two parallel green lines on either side.Cumulative sum (CUSUM) test. Figure by author