gdpCircles = {
let gdpCircles = map.select("#gdpcircles").selectAll("circle")
.data(gdp)
.join("circle")
.transition().duration(500)
.attr("cx", d => projection(getCoord(d["Country Code"]))[0])
.attr("cy", d => projection(getCoord(d["Country Code"]))[1])
.attr("r", d => rFromArea(Math.abs(d[year])) * dotScaleFactor)
.style("fill", d => colorScale(toNum(d[year])));
return gdpCircles;
}