Data labels inside the slice of piecharts - Google Charts api

Question

I am trying to generate an < img src > tag for including in an email report, for which I am using Google charts api to generate an image using the following URL.

I have my URL something like this:

https://chart.googleapis.com/chart?cht=pc&chco=f6c23e%2Cae7f06%2Cffdf8d&chd=t:60,7,167&chs=275x100&chl=High(25.6%)%7CMedium(3.0%)%7CLow(71.4%)

The challenge is that I need to show the percentage numbers marked in brackets inside the slices of pie-charts [25.6% , 3.0%, 71.4%].

Kindly let me know if there is any attribute or parameter which allows to do that. Any help is appreciated.