Why on earth did PSE reduce rates in 2017, 2018 and 2022?

Usually, when utility companies raise rates, they do not reduce them in the future from my past experiences. In fact most businesses do not reduce prices once they raise them.

So while almost everyone who sees the above chart is rightfully shocked by 2023 and 2025, I am even more shocked by 2017, 2018 and 2022.

Chart shown in this post is from the following link:

https://www.swiftwaterelectricandsolar.com/blog/pse-rate-forecasting-for-the-future