Business dynamics in an industry is generally seen as an important indicator of the industry's level of competitiveness and economic performance. Two types of business dynamics may be distinguished: business dynamics reflecting competition by new-firm entries and business dynamics reflecting competition among incumbent firms. A growing literature pays attention to the important role of the former type of business dynamics (the starting up of new firms) for achieving economic growth. However, the latter type of business dynamics tends to be overlooked in this type of literature. In part this is due to the large requirements, both in terms of data and in terms of methodology, of measuring competition among incumbent firms. A sophisticated indicator for measuring the extent of business dynamics among incumbent firms in an industry is the mobility index. In the current paper we compute mobility indices for 16 industries -covering the whole private sector except for the primary sectors of economy- in the Netherlands over the period 2000-2006, and compare the values of the mobility indices across the sectors.