The 2007 Porsche Tennis Grand Prix was a tennis tournament played on indoor hard courts. It was the 30th year of Porsche Tennis Grand Prix, and was part of the Tier II Series of the 2007 WTA Tour. It took place at the Porsche Arena in Stuttgart, Germany, from October 1 through October 7, 2007
The 2009 Porsche Tennis Grand Prix took place at the Porsche Arena in Stuttgart, Germany, from October 1 through October 7, 2009.
We don't know when the 2009 tournament was held, if one was held at all. It's difficult because the statement looks very similar, but not identical to a statement from the passage, so the system assumes it must be incorrect.