Given this paragraph about video games in the Netherlands, how many people work in the games industry?

The Netherlands' mainstream video games market, not taking into consideration the serious and casual games, is the sixth largest in Europe. In 2008, the Dutch market took up 3.95% of the entire European market in total sales and 4.19% in software sales.[1]

A significant part of the Netherlands' gaming industry is in serious games, in which Dutch companies make a significant part of the worldwide industry.[2][3]

In the Netherlands, an estimated of 4,000 people are working in the games industry, at more than 600 companies.[4] Over 45 of the companies are located in the Dutch Game Garden, a government subsidized organization with the aim of promoting and improving the video games industry in the Netherlands.

4,000