nominally significantp = 0.0409
For the post-2020 slope-change term (β 3 ), the arithmetic mean result remained significant after Bonferroni correction (adjusted p = 0.0165), whereas the harmonic mean result, although nominally significant in the unadjusted analysis (raw p = 0.0409), no longer met the corrected significance threshold (Bonferroni-adjusted p = 0.1227; BH-adjusted p = 0.0614).