What does it mean to be in the middle of six years?

Tai sui refers to the annual expenditure of that year. For example, 20 10 this year is the year of Geng Yin, so this year's Tai Sui is Yin; 200 1 is a new year, so 200 1 is a traditional year. If it is a divination from this year, the yin in the divination is close to old age. If it's 200 1, it's the old times and has nothing to do with the sun and the moon. If it is a long-term thing, Tai Sui changes with the dating.