sentences:  When the park opened its total surface area was 9000 m² (2.2 acres), but the park expanded and as of 2007, the park covers a surface area of 17'000 m² (or 4.2 acres).In 1989, the park possessed only 2 locomotives (one running on benzine and one on steam).As of 2007, the number of trains running on benzine has sextupled while the number of steam trains has increased to 9 trains.