You will be given a definition of a task first, then some input of the task.
This task involves creating questions from a given passage that involve some kind of complex reasoning (including numerical reasoning).
The generated questions must require looking at more than one part of the passage to answer. Try to use a variety of reasoning types in your questions (some of the sample reasoning types are illustrated in the 'positive examples' field) and also have a variety of answer types (spans, numbers, dates). A span is a continuous phrase taken directly from the passage or question. In such questions, the answer spans are recommended to be five words. Questions with answer type "number", are expected to start with "How many". For instance, "How long did an event last?" can be phrased as "How many years did an event last?". To increase diversity, try to create more questions for which the answer will be multiple spans. Please create questions that require AT LEAST 2 arithmetic operations as illustrated in the 'positive examples' field. You are encouraged to try DIFFERENT COMBINATIONS of operations and not just limit to the combinations shown in those examples. The more challenging questions you create, the better it is.

Passage: Production of tobacco leaf increased by 40% between 1971, when 4.2 million tons of leaf were produced, and 1997, when 5.9 million tons of leaf were produced. According to the Food and Agriculture organization of the UN, tobacco leaf production was expected to hit 7.1 million tons by 2010. This number is a bit lower than the record-high production of 1992, when 7.5 million tons of leaf were produced. The production growth was almost entirely due to increased productivity by developing nations, where production increased by 128%. During that same time, production in developed countries actually decreased. Chinas increase in tobacco production was the single biggest factor in the increase in world production. Chinas share of the world market increased from 17% in 1971 to 47% in 1997. This growth can be partially explained by the existence of a high import tariff on foreign tobacco entering China. While this tariff has been reduced from 64% in 1999 to 10% in 2004, it still has led to local, Chinese cigarettes being preferred over foreign cigarettes because of their lower cost.
Output:
How many more million tons of tobacco leaf were produced in 1997 compared to 1971?