Figures 12 and 13 are different views of the data in the file "Figure_12_13_data.csv". These data are in WKT format with columns "geometry" and "pm25road". The geometry CRS is EPSG:28992 (Amersfoort / RD New) and the pm25road are in microgram per cubic meter. The figures were created using QGIS 3.16. The color scale was determined using the "Equal Count (Quantile)" classification option of QGIS. The full style is provided in "Figure_12_13_style.qml".