Houten was not included in the survey. They only considered cities above 250k population and then somehow limited it to 100 cities. They also only consider the five best cities that participated in their survey, which mostly affected a bunch of large cities in Germany, including Berlin and Hamburg.
The 2025 Index ranks 100 cities which have been carefully selected in a transparent, multi-step process. The selection started off with a list of all urban areas of more than 250,000 inhabitants, while also including capital cities with smaller populations when their cycling modal share had become significant.
Houten was not included in the survey. They only considered cities above 250k population and then somehow limited it to 100 cities. They also only consider the five best cities that participated in their survey, which mostly affected a bunch of large cities in Germany, including Berlin and Hamburg.