Why Didn't Nus Domis Compose That Many Quatrains?

Nostrodomus was summoned by the queen of france, catherine de medici. In his almanacs he had mentioned something vague, but really bad happening to her husband,. The reason this was scary was cause it implied that some would die. Gerson explains the odd number of quatrains remains mysterious. He may have written one thousand, but we don't know why only 900 forty two were published.