Detailed Instructions: This task involves annotating the answer type to a given question that involve some kind of complex reasoning (including numerical reasoning). Note that the questions require looking at more than one part of the passage to answer. There are 3 possible answer types (i) spans, (ii) numbers and (iii) dates. If the answer can be found in the passage, label it as "span". If the answer is a number, label as "number". Similarly, label "date" if you think the answer to the given question is a date.
Q: Passage: Sir Ralph Moore and the Royal Niger Company had planned the attack on the Aros and the Ibini Ukpabi oracle since September 1899 but due to lack of necessary manpower, it was delayed until November 1901. On November 28, Lt. Col. Arthur Forbes Montanaro led 87 officers, 1,550 soldiers and 2,100 carriers in four axes of advance to Arochukwu from Oguta, Akwete, Unwana and Itu on a counter-insurgency campaign. As expected, Aro forces resisted all axes strongly, although they lacked modern weapons. However, Arochukwu was captured on December 28 after four days of fierce battles in and around the city. As a result, the Ibini Ukpabi shrine was allegedly blown up. Battles between British and Aro forces continued throughout the region until spring 1902 when Aro forces were defeated in the last major battle at Bende. The Aro Expedition ended three weeks later.
Question: How many years after Sir Ralph Moore and the Royal Niger Company planned an attack on the Aros and the Ibini Ukpabi oracle was it delayed?
A:
number