The observed ranges of CP fractions and LP fractions for repeating FRBs. The red point: FRB 121102A (3–5 GHz, PA constant, Michilli et al. 2018; Hilmarsson et al. 2021); the red arrows: FRB 121102A (1–1.5 GHz, PA constant, Plavin et al. 2022); the blue arrow: FRB 180301A (1–1.5 GHz, PA constant or varying, Luo et al. 2020); the orange arrows: FRB 180916B (0.3–1.7 GHz, PA constant, Nimmo et al. 2021; Sand et al. 2022); the orange line segment: FRB 180916B (0.1–0.2 GHz, PA constant, Pleunis et al. 2021); the purple arrow: FRB 190520B (2.8–8 GHz, PA constant, Anna-Thomas et al. 2022; Dai et al. 2022; Niu et al. 2022); the black point: FRB 190604A (0.4–0.8 GHz, PA constant, Fonseca et al. 2020); the pink line segments: FRB 201124A (0.7–1.5 GHz, PA constant or varying, Hilmarsson et al. 2021; Kumar et al. 2022; Xu et al. 2022; Jiang et al. 2022). The arrows denote the upper/lower limits of observations and the line segments denote the observed ranges of CP and LP.