I want to know the answer to the following question:
According to Shuman, up to what percentage of domestic hot water can be  provided by solar heating systems?
All the background I'm provided with is that "In low geographical latitudes (below 40 degrees) from 60 to 70% of the domestic hot water use with temperatures up to 60 °C can be provided by solar heating systems.". Is that enough to answer the question?
Answer: yes