Unfortunately, your question calls to mind someone's signature here that I remember, "Nobody tanks in a void".
The meaning is that tanking is not isolated enough to simply answer that way. DPS tends to be very isolated to your own actions. Tanking is a more complex combination of the tank's actions and the healers. The answer to your question very much depends on your healers as well. I would communicate with them to see how often they feel you are in an "emergency" mode. How often do they have to focus exclusively on you? If you are getting to Elegon, however, it seems to me that is lower than normal.
"he doens't need healing, he doesn't need healing, he doesn't nee-WHAOSHIT!wtf was that man!". Please stop leaning on TDR. -Teng