Demographics of Belgium
Belgium's three official languages are Dutch, spoken by 59% of the population, French, spoken by 40%, and German, spoken by less than 1%. The vast majority of Belgium's population, 99%, is literate as defined by the Belgian government, i.e. capable of reading and writing in an official language by the time a citizen has reached the age of 15.
Dutch in Belgium
Based on differences sources, the number of Dutch speakers in the Brussels-Capital Region can currently be estimated at 5 to 8 percent.
In 2011, on average 7% of the Brussels customers of the largest Brussels telecom operator Belgacom received their invoices in Dutch, 91% in French and 2% in another language. 
The number of Dutch-language invoices turned out to be considerably higher in the northeast of the region than in the southwest (8 to 12% versus 3 to 5%).
Dutch is the official language in Flanders, but there are a number of Flemish municipalities in the Brussels Periphery with a French-speaking majority, which are officially Dutch-speaking with French-language facilities.