Okay, let me see if I've got this right:
2008 - 19,512 lowered to 18,000
2009 - 35,453
2010 - No Record
2011 - 30,004
2012 - 35,986
2013 - 3954 (guessing you've missed a digit off, input error ?)
2013 - 40,000
When you look at it like that, the car has averaged 5,000p/a
If the 2009 figure was 25k rather than 35k everything would look right. To me it's just been an input error (see above, they do happen) they've pressed 3 rather than 2.
The alternative is that in one year they did 15k, rolled the clock back for the next then did a constant 5k for the next 3 years, doesn't seem likely.
The auctioneer has a duty to give correct information.
If the car had "warranted mileage" in the catalogue then you can only treat that as an "indication", the contract is what he actually says on the podium, so if you REALLY want to push it you'd need a copy of that (it's recorded), but you will have to pay for it.