Wanted to number of the Worker Threads in used for my Web Application currently

As per my knowledge, the value of the Worker Threads is controlled using the ProcessModel tag of Machine.Config in one of the two ways:
1. If AutoConfig value is true, then, it will be taking default 100 per CPU
2. If AutoConfig value is false, then it will be taking the value that is specified per CPU

We used the following link: http://support.microsoft.com/kb/821268

So, according to what all I have understood, if we have a web application which is not that CPU intensive and can easily take in more requests per second, then you can increase this value. Especially if your Web application uses a lot of Web service calls or downloads/uploads a lot of data which does not put pressure on the CPU. When ASP.NET runs out of worker threads, it stops processing more requests that come in. Requests get into a queue and keep waiting until a worker thread is freed. This generally happens when a site starts receiving much more hits than you originally planned. In that case, if you have CPU to spare, increase the worker threads count per process.

But, my problem is, I want to know, the exact value of Worker Threads that are used at any given particular time so that I can decide to what value should I increase this parameter, or shall I keep it what it is. Is there any Performance Counter or any other way to know that?

Please let me know. I have searched a lot, but was unable to find it.