Mileage

Just did a HPI check on a car I was thinking of buying. The car is advertised for 61,000 and the mileage check flagged up a discrepancy. The last record goes down a small amount rather than up. Does this look strange or could there be an explanation? Car had mot January 16 and miles where around 53,000. Asked this question elsewhere and was told it looks like the car has been unused for almost a year. Where did they get that information. Could it be that the last two figures are guesses of some sort which would make the mot mileage figure correct and the miles on it now as well? I am clueless.

07/01/2015 Manufacturer 38814 19/01/2015 BVRLA 39188 11/03/2015 Manufacturer 42001 10/05/2015 Manufacturer 45417 03/07/2015 Manufacturer 51286 09/10/2015 BVRLA 62925 24/06/2016 BVRLA 62359