I get the same OVT 1,897 .
Here is my thinking on it , I could be way off though.
The site assiter.com has a true OVT of 40 , an auctioneer for real estate , so possibly last month they had maybe an auction publisized heavily but the advertising was misspelled in the newspapers, then it got a ton of people to your assitter.com , so maybe a temporary spike in OVT for last month.
How is that for a wild guess.