Hi, first time using this plugin.

Using a simple JMeter JMX and freestyle project in Jenkins to run it.

In the post-build I'm trying to use the performance plugin to compare results with previous build. Numbers are showing up for each build but the difference is always zero.

I've checked the console output and the plugin seems to be finding differences, but nothing appears in the table (see screenshot).

Here are the last lines from the Console Output :

```

15:35:06 Project_R02_Conf 20 21 1 5.00%
15:35:06 Project_R02_Conf 20 20 0 0.00%
15:35:06 Project_R02_Conf 20 21 1 5.00%
15:35:06 Project_R02_Conf 20 22 2 10.00%
15:35:06 Project_R05_Footer 45 43 -2 -4.44%
15:35:06 Project_R05_Footer 45 45 0 0.00%
15:35:06 Project_R05_Footer 45 42 -3 -6.67%
15:35:06 Project_R05_Footer 45 45 0 0.00%
15:35:06 Project_R06_BonsPlans 107 123 16 14.95%
15:35:06 Project_R06_BonsPlans 107 107 0 0.00%
15:35:06 Project_R06_BonsPlans 107 111 4 3.74%
15:35:06 Project_R06_BonsPlans 107 91 -16 -14.95%
15:35:06 TOTAL_Project 556 578 22 3.96%
15:35:06 TOTAL_Project 556 556 0 0.00%
15:35:06 TOTAL_Project 556 547 -9 -1.62%
15:35:06 TOTAL_Project 556 529 -27 -4.86%
15:35:06 Finished: SUCCESS```

And see screenshot --> show 0 difference.