Question: The manufacturer of Premarin was purchased by Pfizer in what year?

Context articles: Mcity
Lubriderm
North Carolina International Port
NoPort Southport
Schick (razors)
Halls (cough drop)
Sitaxentan
Doctor's Data
Premarin
Wyeth

Mcity is a 32 acre mock city and proving ground built for the testing of wirelessly connected and driver-less cars located on the University of Michigan North Campus in Ann Arbor, Michigan.
 The project, which officially opened on July 20, 2015, is built on land purchased by the university from a former Pfizer facility.
 It cost US$10 million and will be collaboratively managed by Mcity (formerly the Mobility Transformation Center - MTC).
 In November 2015, Ford Motor Company announced that it is the first car company to use the new facility.
Lubriderm is a hand and body lotion first created by the Texas Pharamacal Company of San Antonio.
 The company was sold to Warner Lambert and later Lubriderm was sold to Pfizer.
 It was then purchased by Johnson & Johnson and is now one of their consumer products.
In early 2006 the North Carolina State Ports Authority (NCSPA) conceived its proposal for a North Carolina International Terminal to be created on property that it purchased just north of the town of Southport, NC between the Progress Energy Brunswick Nuclear Power Plant and the Sunny Point Military Ammunitions Port.
 The NCSPA purchased the property in early 2006 for $30 million from Pfizer.
 Eleven years later the proposal, having met substantial public and political resistance, will not likely move forward in the foreseeable future.
NoPort Southport NC, Inc., is a grassroots organization of citizens of the lower Cape Fear region of North Carolina, formed in 2008 to oppose the development of the North Carolina International Terminal (NCIT).
 The NCIT project, initiated by the North Carolina State Ports Authority (NCSPA), would construct a large container terminal (megaport) on an undeveloped site on the Cape Fear River near Southport that they had purchased from Pfizer in 2006.
Schick is a brand of personal care and safety razors owned by Edgewell Personal Care.
 The company was founded in 1926 and was purchased by Energizer in 2003 from Pfizer.
 On July 1, 2015, Energizer split into two companies with Schick falling under Edgewell Personal Care.
Halls is the brand name of a popular mentholated cough drop.
 Halls cough drops (categorized as a cough suppressant/oral anaesthetic by the manufacturer) are sold by the Cadbury-Adams Division of Cadbury, now owned by Mondelēz International, and have long been advertised as featuring "Vapor Action".
 Halls was first made in the 1930s in Stanley Road, Whitefield, Lancashire, United Kingdom by the Halls Brothers company (founded 1893).
 Halls Brothers was acquired by Warner-Lambert in 1964.
 Production in Whitefield ceased in the late 1980s.
 When Pfizer acquired Warner-Lambert in 2000, the Halls brand came with the entire Adams portfolio (which included Trident gum, Dentyne, Chiclets and Freshen Up, among others).
 Two years later, Adams was bought out by Cadbury, who were subsequently purchased by Kraft foods, which was later restructured and renamed Mondelēz International - as of 2015, Mondelēz International owns the Halls brand worldwide.
Sitaxentan sodium (TBC-11251) is a medication for the treatment of pulmonary arterial hypertension (PAH).
 It was marketed as Thelin by Encysive Pharmaceuticals until Pfizer purchased Encysive in February 2008.
 In 2010, Pfizer voluntarily removed sitaxentan from the market due to concerns about liver toxicity.
Doctor's Data, Inc. is a laboratory based in St. Charles, Illinois selling hair analysis and urine analysis tests.
 Founded in 1972, it was originally known as Bio Medical Data, Inc. until the early 1980s, when it changed its name to Doctor's Data.
 It was originally owned by Miller Pharmacal, which was founded by John J. Miller, former research chemist for J.B. Roerig, which was purchased in 1953 by Pfizer.
 Miller died in 1977; since then, Ted Lucken has been the president of the organization.
Premarin is the brand name for an estrogen medication that consists of conjugated estrogens isolated from the urine of pregnant mares (pregnant mares' urine).
 It is manufactured by Wyeth (now a part of Pfizer), and was first marketed in 1941 and 1942 in Canada and the United States, respectively, for the treatment of menopausal symptoms.
Wyeth was a pharmaceutical company purchased by Pfizer in 2009.
 The company was founded in Philadelphia, Pennsylvania, in 1860 as John Wyeth and Brother.
 It was later known as American Home Products before being renamed to Wyeth in 2002.
 Its headquarters moved to Collegeville, Pennsylvania, and Madison, New Jersey, before its headquarters were consolidated with Pfizer's in New York City after the 2009 merger.
 The infant and maternal nutrition business was acquired by Nestlé in 2012.