Annual average count of U-Net identified PFe (in solid color) without accounting for projection issues. The annual average was computed by taking the first week of September (for north pole) and March (for south pole) until 2021. Fainter color points shows projection-corrected measurements derived from an entire daily time series, and then taking averages of the first week of September and March as the end value. The sign was adjusted based on the sign of the average WSO polar magnetic field, following the method by Hovis-Afflerbach & Pesnell (2022). The polar regions under consideration were those with |φ_⊙|≥70°.