200.9×191.2-2010×19.11

=2009×19.12-2010×19.11

=（2010-1）×19.12-2010×19.11

=2010×19.12-19.12-2010×19.11

=2010×（19.12-19.11）-19.12

=2010×0.01-19.12

=20.1-19.12

=0.98．

故答案为：0.98．