in 2014, 17% of people in Texas lived under the poverty line, and the tendency is somehow falling: it's around 15 % now.
It was 15% also around 2000, and then for some years the number of people under the poverty line rose - with a peak of 18.5% in 2011, after which it began falling again.
While poverty is a complex phenomenon, we can imagine that the global financial crisis had a a lof of influence on the poverty line in Texas.