1 group of indoor activities, the other of outdoor ones
1 group of the upward trend, the other of the downward trend
the fastest change
1 group of public transport, the other of private transport
the lowest + highest numbers
equal numbers
number 0, missing information
1 group of Ameriacan continent, the other of Europe
1 group with more males, the other group with more females
1 group of developing countried, the other group with developed counterparts
1 group of land travel, 1 group of air travel, and the other group of sea travel
the greatest difference
1 group of one way development (up and/or downe), the other with fluctuations
adding numbers together and make comparisions
the trend (the starting, ending figures + sth else necessary)
grouping information
identifying the correlations between 2 or more graphs
