The National Crime Agency regularly publishes National Referral Mechanism (NRM) data, including the “National Referral Mechanism Statistics Annual Report 2018” on 20th March 2019, available at:
These published statistics include a summary of current status for cases between 2013 and 2018, including numbers of cases pending a NRM decision (Reasonable Grounds and Conclusive Grounds combined).
The statistics also provide the decision status of 2018 cases, including those pending a Conclusive Grounds decision (as at 12 March 2019), split by grouped nationalities (UK, EU (non-UK), Other, and Not Known), and by claimed exploitation type.
The statistics also detail the number of cases allocated to each Competent Authority in 2018, however the published statistics do not provide breakdown of pending decisions by Competent Authority, i.e. National Crime Agency and UK Visas and Immigration.