People are putting off marriage to later ages. People are more likely to think that premarital sex is morally justifiable. People of marrying-age are more activ

People are putting off marriage to later ages. People are more likely to think that premarital sex is morally justifiable. People of marrying-age are more active participants in the work force. Historically, if you were a median woman you needed marriage to have access to a stable income. If you were a median human, you needed marriage to have socially-acceptable sex. Nowadays, people in their 20s have many paths to wealth and sex that do not require the commitment of marriage. People can remain financially and sexually independent for more of their lives (feasibly indefinitely), which means they can be more choosy with their marriage partners. This implies fewer and happier marriages, and a lower divorce rate. That's my interpretation of the presented data, anyways.