Suppose that NASA decides to send the expedition at a time near solar maximum. By the time you return, the conditions in space will be near those at solar minimum during the solar cycle which occurs about 5.5 years after solar maximum. During solar minimum, the Sun is relatively inactive and allows GCRs to reach the inner solar system in greater numbers. The integrated dose of GCRs is about 2.5 times higher at solar minimum than at solar maximum. Also, you will need to calculate the total exposure over the entire 4.3 year trip.
Total exposure is measured in units of rems.
Your trip begins during solar maximum and ends during solar minimum.