According to Manfred Lebmeier, ESI Bureau Director, 7,227 ships are registered and 56 incentive providers, as of January 1, 2019. Both registered ships and incentive providers increased from 7,049 to 7,227 (+178) and from 53 to 56 (+3) respectively compared to October 1, 2018.
More details on ESI website: http://esi.wpci.nl/Public/Home