Q: 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.
Passage: The War of the Spanish Succession ended with the Treaty of Utrecht in 1713. The colonial borders of northeastern North America were reshaped as a result, but the treaty did not account for Indian claims to the same area. French Acadia was ceded to Great Britain which established the province of Nova Scotia, although its borders were disputed. The area disputed by the European powers consisted of land between the Kennebec River and the Isthmus of Chignecto . This land was occupied by a number of Algonquian-speaking Indian tribes loosely allied in the Wabanaki Confederacy, which also claimed sovereignty over most of this territory and had occupancy preceding that of the Colonists. Massachusetts Governor Joseph Dudley organized a major peace conference at Portsmouth, New Hampshire. In negotiations there and at Casco Bay, the Wabanaki present orally objected to British assertions that the French had ceded their territory to Britain in eastern Maine and New Brunswick, and agreed to a confirmation of boundaries at the Kennebec River and the establishment of government-run trading posts in their territory.:162-163 The Treaty of Portsmouth was ratified on July 13, 1713 by eight representatives of the Wabanaki Confederacy, however, which asserted British sovereignty over their territory.:107-110 Over the next year, other Abenaki tribal leaders also signed the treaty, but no Mi'kmaq ever signed it or any other treaty until 1726.:97-98
Question: Which year did other Abenaki tribal leaders sign the Treaty of Portsmouth?
A:
date