Study the above chart and you quickly see that Dallas ISD made very solid progress for most of this decade. It was only surpassed by Cedar Hill ISD for whom the past two years are the worst on the chart, but the achievement remains since 2005.
This chart does not include the 2015 calculations that show the DISD Student Achievement Gap growing another 2 percentage points. Such calculations are only projections and require time to calculate.
Below is the data used to create the above chart along with the calculations required.
You can see with the last line in the chart above that the average of these 5 schools made a full percentage point gain in shrinking their achievement gap. Dallas ISD, even if you include the loss from next year, will still be within that level of gain.