Its actually 93 which means that their were reactions that were removed.
Reaction counts do NOT recount on change of a total (negative, positive or neutral, they also don't recount if you remove a reaction that did any of those).
So if you had one that added reputation and deleted it, it wouldn't delete the existing total unless you recount their reputation total.
Additionally, if you make a positive a neutral reaction it will never add the past reactions as neutral because when someone reacted it was a positive so those reactions will always be positive but future reactions will be neutral.