Some hosts give very low priority to, or don't respond to pings all together. It is a form of protection, and if a certain hop does not ever respond to pings it is not an indication of a problem.
That said, you have a very large latency increase between hop 7 and 9, this may be a problem. To see what causes the issues, compare traces when your connection is good, and when it seems bad during peak hours, look for difference in latency to each hop.. Look for a host that gives you low latency and no packet loss when your connection seems good, but huge latency and some packet loss when your connection seems bad. This is usually the culprit.
It is also dependent on other factors as well, such as your modem signal levels, how clean your line is. I hope this helps.