Dutch dialects and regional languages are not spoken as often as they used to be. Recent research by <answer>Geert Driessen</answer> shows that the use of dialects and regional languages among both Dutch adults and youth is in heavy decline. In 1995, 27 percent of the Dutch adult population spoke a dialect or regional language on a regular basis, while in 2011 this was no more than 11 percent. In 1995, 12 percent of the primary school aged children spoke a dialect or regional language, while in 2011 this had declined to 4 percent. Of the three officially recognized regional languages Limburgish is spoken most (in 2011 among adults 54%, among children 31%) and Dutch Low Saxon least (adults 15%, children 1%); Frisian occupies a middle position (adults 44%, children 22%).
What organization researched the use of regional Dutch dialects and found their usage declining?
Geert Driessen