I don't think that's quite the right question to ask. The _reason_ for the divorce is such an important factor. The divorce rate for verbally/physically abusive marriages should be 100% (ideally 100% of a very small number). The divorce rate due to financial stress should be 0% but is currently being artificially skewed by fiat money. I don't think having a divorce rate of 1% is inherently bad if it is an accurate reflection of people's happiness with their relationship choices.
Discussion
Well I agree with a lot of you thinking here, but it's just a miracle that people can grow and change in the same direction with another human for decades on decades in a row! Even in non-abusive relationships I don't think it's a good idea to expect 0%.