Why does my security test take more than 2 hours? It ran around 28 thousand requests.

I am running a security test with 228 parameters and with all security scans with the base functionality that comes with the SoapUI NG. I started the test around 2 pm and closed it around 4 when I was about to leave. It ran around 28000 requests and 17 thousand of them were for cross site scripting. Is it normal to take that long? How can I improve it?

Thanks,

Sari