显示GroupBy ASP.NET MVC的第一个实例和最后一个实例

I have a dashboard that shows an updated list of application errors. Some errors have happened more than once so I have grouped them by their error type and placed a count on them to see how many times this error has occurred. I am wanting to find out when the first date the error occurred, which is fairly straight forward, but also the last date it occurred too to see how long this error has been persisting.I have a dashboard that shows an updated list o