well no need to get all smartarse about it, but sorry, there are only 2 unique 28 year periods. using 33 data points which share much of the same data is useless as it overconfirms any conclusions that you can come to in doing so.
Well if we are looking over the last 300 years, certainly most debt was not the place to be. Most fiat currencies have ceased to exist, and/or are worthless in terms of their purchasing power. Also the Dutch East India Company stock paid an 18% annual dividend for well over 150 years, before falling to zero. So there is a time and place for every asset. Debt certainly went to zero in Russia, China, the Confederate States and numerous other countries. Numerous canal and railroad debts went to zero, whether in the US, Europe or Latin America. Selected land, some art, gold, and certain rare manuscripts, wines, jewels, and rare musical instruments (all ex land & gold only if stored properly)were broadly the holders of value through numerous wars, plagues, etc… Thus the propensity of European dynasties to use tangible assets as a store of wealth and an integral part of their asset allocation.