Time-dependent fractional LP measurements obtained at 86.3, 100.3, and 229.1 GHz presented on the 𝒬/ℐ − 𝒰/ℐ plane of linear polarization, compared with the past measurements at the corresponding frequencies. The colors denote the time progression, following the colorbars. The polar coordinates indicate fractional polarization (in %) and EVPA (in degrees; 0° ≡180° corresponds to EVPA aligned with the north-south axis).