Newly released national high school graduation rates show improvement across the board, including in Florida. But Florida continues to sit near the bottom of the pack, despite its growth. The 2014-15 data, distributed by the White House on Monday in advance of an education speech by President Barack Obama, shows Florida had a 77.9 percent graduation rate. That’s up from 76.1 percent a year earlier. It’s also below the national rate of 83.2 percent, and well behind the top states of generally homogenous Iowa (90.8 percent) and more diverse New Jersey (89.7 percent).