I am trying to make a pie chart of value added by economic activity (as a % of gdp). I am trying to use data from world bank for each of the four sectors: manufacturing, agriculture, industry, services http://data.worldbank.org/indicator/NV.IND.TOTL.ZS?display=default , but surprisingly the percentage share for each of those sectors, for one country do not add up to 100 but to 120. Why is that?
The first line of your World Bank link gives you the explanation:
Industry corresponds to ISIC divisions 10-45 and includes manufacturing (ISIC divisions 15-37)
Hence, if you add up industry and manufacturing you count some activities twice, the divisions 15-37 that is.
But even if you take this into account you should not find 100% if you are adding up the value added of all the activities. Gross domestic product (GDP) is not the sum of the gross value added (GVA) of all the activities but:
GDP = GVA + Taxes on products - Subsidies on products
According to Statistics Explained
Gross value added of the total economy usually accounts for more than 90 % of GDP
So, the message is to check carefully the definitions and concepts used by the World Bank.