 Enthusiasm for the newer clones often remains low owing to the poor performance of earlier, supposedly disease-resistant Dutch trees released in the 1960s and 1970s.In the Netherlands, sales of elm cultivars slumped from over 56,000 in 1989 to just 6,800 in 2004, whilst in the UK, only four of the new American and European releases were commercially available in 2008.New York City's Central Park is home to approximately 1,200 American elm trees, which constitute over half of all trees in the park.