Well knowing that a plants tissue is mostly water...I would say if properly dried and cured you'll lose a third of the weight from water. KEEP SMOKE ALIVE!!
Your plant is in flower and you will see more yellowing as the plant uses the sugars and energy from the larger leaves to feed the flowers. KEEP SMOKE ALIVE!!
I'm growing Purple Humboldt, Acapulco Gold, Pure Indica(One of my own :] )Northen Lights x Kush, and last but not least some whites. KEEP SMOKE ALIVE!!