Complex sentence: On September 29, in a letter to Morgenthau, Jackson placed the survival rate of the deportees at about 15 percent and further notes that this had amounted to the deaths of about 1,000,000 Armenians.
Split into simpler sentences: On September 29, in a letter to Morgenthau, Jackson placed the survival rate of the deportees at about 15 percent. He further notes that this had amounted to the deaths of about 1,000,000 Armenians.