How can I capture how long waitFor() waited?

I'm using casperJS to test one application. Thing is, I want to capture how long it actually took to receive the element I'm waiting for with waitForSelector().

If I set the log level to debug, it shows in the console how long it took for the element I was waiting for to appear:

I want to get that value and store it in a variable. Is this possible with CasperJS / PhantomJS? If it's not, what framework could I use instead?