地图上颜色深的部分代表什么？

What do the shaded areas on the map represent?

《牛津词典》

叫做等值线图的特殊地图使用地图的颜色来表示统计数据。

Special maps called choropleth maps use map color to represent statistical data.

youdao

我很好奇，我要为欧洲地图上所有那些地方涂上颜色。直到那时，那些部分都是灰色的。

I was curious: I wanted to colour in all those parts of the European map that had until then been grey.

youdao