Leiden is home to couple of fine museums one of which is Museum Volkenkunde (Museum of Ethnology). At the moment there is an exhibition on the Hajj, the pilgrimage to Mecca called 'Longing for Mecca'. It's on display until March 8th so you have to quick to go and see it.
My girlfriend, Elke Spiessens, did some research for this exhibitions especially tying to find the numbers behind the Hajj. Such as how do people travel to Mecca, or how many stones were used to throw at the Jamarat (stoning of the Devil) and also how many people travel from which country.
That last one struck me as an opportunity to make a nice visualization. These numbers are hard to find exactly and for a lot of countries they couldn't be found so there are some gray spots on the map.
In this map I included a bar plot so you can compare the different countries a bit easier and I thought filling in the numbers with arrows to the countries gives you a bit more feeling than just the colors. Small note, I didn''t have the number of pilgrims that comes from inside of Saudi Arabia. Also most numbers are estimates and based on quotas that are set. So every country can only send a certain amount of pilgrims, which is done for crowd control. The Hajj take place during 5 days in which over 3 million pilgrims visit Mecca and the surrounding sites.
Muslims per country
Looking back at this map I can strike you as odd. The top three countries that send the most pilgrims are Indonesia, Pakistan and India, where the first and third might not fit your typical middle eastern Muslim premise.
If we look at the map found of Wikipedia showing the percentage of Muslims per country we see the following.
|The percentage of Muslims per country|
Which is I guess more what you'd expect. Countries in the Middle East and Northern Africa colored dark where a large majority of the people are Muslim (sometimes close to 99%). If you look carefully you can already see that Indonesia has a large Muslim majority (about 86%). But if we look at the map showing the absolute number of Muslims per country we can understand the map with the number of pilgrims a lot better.
|Absolute number of Muslims per country|
This map also comes from Wikipedia and can immediately see what's happening. The top three countries Indonesia, Pakistan and India have a lot of citizens and so even if the percentages aren't as high as the Middle Eastern countries it adds up. So it turns out that almost two-thirds of the Muslims live in Asia-Pacific and I think that is a nice eye-opener.
How it's made
I just want to say a few words on how this map came together. As I mentioned in previous posts a great inspirational source is Visualize This by Nathan Yau and making this map was helped a lot by the examples found in that book. The data I had was run through a Python script to create the CSS styling needed to color in the SVG map. The bar plot was made in R, exported as a PDF, imported in Inkscape, styled to fit the map and then added. All the numbers and arrows were put in by hand in Inkscape.
Since this post is more focused on the story than on the technique I hope you find it informative. If you like to learn more about the Hajj and the people that take this pilgrimage go see that exposition before it closes.