National parks in the Netherlands were defined in the 1960s as: "Areas of at least 1000 hectares, consisting of natural terrains, water and/or forests, with a special landscape and flora and fauna. There are good possibilities for recreative use. In the national parks, nature care and nature development is intensified, nature and environmental education, nature oriented recreation and research are stimulated." The first national park, in Schiermonnikoog, was however not established until 1989.
... 25 to 44, 23.8% from 45 to 64, and 7.9% who are 65 years of age or older. The median age is 35 years. For every 100 females there are 95.1 males. For every 100 females ...