The trademark for the term 'Heat map' eventually became annulled in which year, allowing for its universal public use?

Answer

2006

Although Cormac Kinney coined and trademarked the term in the early 90s, and it transferred to SS&C Technologies in 1998, the trademark lapsed and was annulled in 2006.

The trademark for the term 'Heat map' eventually became annulled in which year, allowing for its universal public use?
inventorvisualizationheat map