According to Manfred Lebmeier, ESI Bureau Director, 7,049 ships are registered and 53 incentive providers, as of October 1, 2018. The number of registered ships increased (+158) from 6,895 to 7,049 while incentive providers (53) unchanged compared to July 1, 2018.
More details on ESI website: http://esi.wpci.nl/Public/Home