Sequenced Increment Based On Previous Row Change

I am pretty new to SQL and facing difficulties with a current problem.

I have a list of customers and a sequence of events they have triggered . I know the sequence in which these events have been triggered and only want to increment a value when a new event is triggered (value to remain the same if the event is the same). I have come close to a solution with Dense_rank but the problem here is that the ranking doesn't reset if the same even previously triggered is triggered a bit later in the sequence. see below an example of current results and expected results:

Customer ID,Sequence ID,event,current result,expected result
1,1,A,4,1
1,2,A,4,1
1,3,B,3,2
1,4,C,2,3
1,5,A,4,4
1,6,A,4,4
1,7,E,1,5
1,8,D,5,6
2,1,B,3,1
2,2,C,2,2
2,3,C,2,2