Comparison between VADM curves computed between 1500 BC and 2000 AD using sliding windows of ΔT = 200 years (panels A), C)) and 500 years (B), D)) shifted by 50 years, and using a weighting over regions of ΔS = 10° × 10° (A), B)) and ΔS = 30° × 30° (C), D) width. The thick black line exhibits the averaged VADM computed using a bootstrap scheme (see main text and legend of Tables C.1 and C.2 available at CDS), with its 1σ uncertainties (dotted lines) and the envelope of possible VADM values (gray lines).