proj4.defs("EPSG:28991","+proj=sterea +lat_0=52.1561605555556 +lon_0=5.38763888888889 +k=0.9999079 +x_0=0 +y_0=0 +ellps=bessel +towgs84=565.2369,50.0087,465.658,1.9725,-1.7004,9.0677,4.0812 +units=m +no_defs +type=crs");