When did this happen ? not at a fixed date but gradually as the safety numbers were getting better and better . The graph posted by rcsa above is basically showing you why and when .
The priority of this decade is punctuality , it was fuel a few years back , if was safety 50 years ago, when the numbers were bad and people were afraid to fly.
Today flying is like taking the train , and what the average pax wants today is running on time as well as the lowest price for their tickets . Safety is down the list, so do not expect the young MBAs on they way up the ladder that run our industry to do something else.
Safety is taken for granted by too many , and just like in a marriage, take your partner for granted , and after some years sh'es gone and you are surprised .