sentences:  Over 20% of the Shetland population participate in the event., Da Voar Redd-up has resulted in the removal of 1,900 tonnes of litter from the environment.Shetland Amenity trust organises Shetland Wool Week, which is an annual event held in September-October where knitting enthusiasts from around the world take part in classes and workshops held in venues across Shetland.