This task involves creating answers to complex questions, from a given passage. Answering these questions, typically involve understanding multiple sentences. Make sure that your answer has the same type as the "answer type" mentioned in input. The provided "answer type" can be of any of the following types: "span", "date", "number". A "span" answer is a continuous phrase taken directly from the passage or question. You can directly copy-paste the text from the passage or the question for span type answers. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words. A "number" type answer can include a digit specifying an actual value. For "date" type answers, use DD MM YYYY format e.g. 11 Jan 1992. If full date is not available in the passage you can write partial date such as 1992 or Jan 1992. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words.

Example Input: Passage: Salks vaccine was then used in a test called the Francis Field Trial, led by Thomas Francis, Jr., the largest medical experiment in history at that time. The test began with about 4,000 children at Franklin Sherman Elementary School in McLean, Virginia, and eventually involved 1.8 million children, in 44 states from Maine to California. By the conclusion of the study, roughly 440,000 received one or more injections of the vaccine, about 210,000 children received a placebo, consisting of harmless culture media, and 1.2 million children received no vaccination and served as a control group, who would then be observed to see if any contracted polio. The results of the field trial were announced 12 April 1955 (the tenth anniversary of the death of President Franklin D. Roosevelt, whose Franklin D. Roosevelts paralytic illness was generally believed to have been caused by polio). The Salk vaccine had been 60-70% effective against PV1 (poliovirus type 1), over 90% effective against PV2 and PV3, and 94% effective against the development of bulbar polio. Soon after Salks vaccine was licensed in 1955, childrens vaccination campaigns were launched. In the U.S, following a mass immunization campaign promoted by the March of Dimes, the annual number of polio cases fell from 35,000 in 1953 to 5,600 by 1957. By 1961 only 161 cases were recorded in the United States. 
Question: How many states chose not to particpate in the Salks vaccine? 
Answer type: Number 
Example Output: 6.

Example Input: Passage: Mexicos Gross Domestic Product (GDP) in purchasing power parity (PPP) was estimated at US $2,143.499 1000000000 (number) in 2014, and $1,261.642 1000000000 (number) in nominal exchange rates. It is the leader of the MINT (economics) group. Its standard of living, as measured in GDP in PPP per capita, was US $16,900. The World Bank reported in 2009 that Mexicos Gross National Income in market exchange rates was the second highest in Latin America, after Brazil at US $1,830.392 billion, which lead to the highest Gross National Income in the region at $14,400. As such, Mexico is now firmly established as an upper middle-income country. After the slowdown of 2001 the country has recovered and has grown 4.2, 3.0 and 4.8 percent in 2004, 2005 and 2006, even though it is considered to be well below Mexicos potential growth. 
Question: How many combined growth percentage for 2004, 2005 and 2006? 
Answer type: Number 
Example Output: 12.

Example Input: Passage: A central feature of the white community in Rhodesia was its transience, as white settlers were just as likely to leave Rhodesia after a few years rather than permanently settle; for example, of the 700 British settlers who were the first white settlers, arriving in 1890, only 15 were still living in Rhodesia in 1924. As the white population of Rhodesia had a low birth rate (18 per 1,000 compared to the African rate of 48 per 1,000), to maintain white population growth was largely dependent upon taking in new white immigrants with immigration accounting for 60% of the growth of the white Rhodesian population between 1955–72. However, the American historian Josiah Brownell noted that the turnover rate for white residents in Rhodesia was very high, as Rhodesia took in a total of 255,692 white immigrants between 1955–79 while the same period a total of 246,583 whites emigrated. Even during the boom years of the late 1950s, when Rhodesia took in an average of 13,666 white immigrants per year, mostly from the United Kingdom and South Africa, an average of about 7,666 whites emigrated annually. Between 1961–65, Rhodesia took in an average of 8,225 white immigrants per year while also having an average white emigration of 12, 912 per year. Many prospective white immigrants in Rhodesia arrived seeking economic opportunities and departed with fluctuations in the security situation as the Bush War intensified. A substantial number were uninterested in settling there permanently and did not apply for Rhodesian citizenship, despite a much-publicised 1967 campaign urging them to do so. Brownell asserted that patriotism in the white community was "shallow" due to its essentially expatriate character. Brownell also claimed that the majority of white immigrants in the late 1960s and early 1970s were unskilled laborers who competed with the countrys black African workforce and did not contribute badly needed technical or professional skills to the country. He argued that this was due to a government policy aimed at making white immigration as "unselective as possible" and guaranteeing every white immigrant a job. 
Question: How many more, per 1000,  was the birth rate in Africa than the white population of Rhodesia? 
Answer type: Number 
Example Output:
30.