How the idea for this post was born
Yesterday 
Hive account@dj123 was mentioning that 
Hive account@comedyopenmic dropped out of the top 100 list of witnesses, not far but rank #102. So I decided to ask a sweet dolphin if she had any open slots at the moment. And she did (thank you!), after voting she mentioned they were on rank #88 according to that site. But this isn't really the case. When you vote for a witness they will show you the rank they are on without all the inactive witnesses on higher ranks. But unfortunately those inactive witnesses remain in the list for a long time because people don't remove their votes! Personally I've never been aware of this, but when I checked yesterday I noticed that the inactive witness list is quite long in the top 100, and some of them have been inactive for a long time now. Let's have a look at this image:
9 out of 13 witnesses ranked 91-103
The image above shows the inactive witnesses from position 91 - 103, as you can see 9 out of 13 witnesses in this image are inactive! As an ambassador for comedyopenmic I want to take them as an example here, because they dropped out of the top 100 list, but only looking at the witnesses from position 91 until their spot, this means there are 7 inactive witnesses above them. If people revoke their votes for those inactive witnesses, at a certain point this would mean the active ones move up. In Hive account@comedyopenmic's case this would mean they would probably be at the 95th place.
But there's more
I only showed 10% of the top 100 in this image, let's have a better look at those in even higher positions to have a better idea of how many of your votes are given to inactive witnesses. The amount of inactive witnesses luckily decreases looking at the higher ranks, but I still want to point out to you that if you have given your vote to them, you should better remove those and replace them for active witnesses. Because I believe the witness system is meant to give your vote to people that actively contribute to the Steemit blockchain in their own way right?
So ranks 31 - 90 shows there are 2 other inactive witnesses, if you look at rank 34 you see 
Hive account@jerrybanfield there, who made no secret about the fact that he was disabling his witness server, you can read his post here. He also mentioned in his post that this meant other witnesses had an extra spot in the top list. But as he still is ranked on #34 I assume that many people still didn't revoke their votes for Jerrybanfield?
Now let's have a look at the top 30 witnesses in the list
In the top 30 rank you can see these witnesses are all active, except for one. Have a look:
Rank 31 shows 
Hive account@pharesim who announced he would quit as a witness while ago in this post. I must admit that I also voted for Hive account@pharesim as a witness, and I did not revoke the vote myself until I was preparing this post. As he is still ranked 31 I believe there are many more people that don't know that this vote is useless at this point. I don't know if he will come back as a witness but for now I read that he is enjoying traveling, and I hope he's having a wonderful time.
Edit: thanks to 
Hive account@alexvan's comment I found out the current state of Hive account@pharesim as a witness is unclear at this moment, so hopefully he will read this at a certain point and can write a comment..
What about those outside of the top 100
A quick count from rank 101-200 shows me that 54 out of 100 witnesses are inactive, that's more than 25% ! I hope this post will get people to have a new look at their witness voting behavior, and see if they've voted for inactive witnesses. To hopefully replace those for new active witnesses. I was trying to get some votes for Hive account@comedyopenmic as a witness before I got the inspiration to make this post (thanks 
Hive account@canadian-coconut for your words that pushed me over the edge to actually do so) so I also want to ask people that like comedy to vote for them.
Click To Vote @ComedyOpenMic For Witness And Disrupt The Steem Blockchain With Laughter!
Thank you to 
Hive account@matytan for the great banner
Other witnesses that constantly support comedyopenmic:
Hive account@ausbitbank 
Hive account@nextgencrypto 
Hive account@roelandp
Please consider voting for them too!
If you want to have the most accurate statistics about missed blocks and who are inactive in the witness list, you can check this account 
Hive account@witnessupdate and here you have a link to the most recent post. This way you don't have to do the research yourself, when you are thinking about changing some votes.
All the screenshots in this post come from this list: https://steemian.info/witnesses
