Read this and answer the question. If the question is unanswerable, say "unanswerable".

In January 2010, Hong Kong-based English newspaper The Standard reported that writer Tan Zuoren attempted to document shoddy construction that may have led to massive casualties in schools, was sentenced to in prison ostensibly for his writing an article in 2007 in support of the pro-democracy movement in 1989.

When did the sentencing occur?
in 2007