Percentages and proportions

It is often easier to understand proportions (or percentages) than raw counts. This is particularly important for comparing groups of individuals. The table below shows the origin and 'lifestage' of tourists (in thousands) arriving in Hawaii in 2005.

  US West US East Japan Canada Europe
Wedding/honeymoon 103.1 110.0 192.7 8.0 131.5
Family (with children) 667.1 297.1 485.6 44.5 94.4
Young (18-34) 403.3 243.1 229.1 38.8 210.1
Middle aged (35-54) 955.2 634.7 308.0 75.1 374.2
Seniors (55+) 903.7 643.5 303.5 82.3 314.6
Total 3,032.5 1,929.3 1,517.4 248.6 1,123.7

The information is easier to understand as percentages within each country of origin. Scanning across rows in the table below, the highlighted percentages stand out as 'unusual'.

    US West   US East Japan Canada Europe
Wedding/honeymoon 3.4 5.7 12.7 3.2 11.7
Family (with children) 22.0 15.4 32.0 17.9 8.4
Young (18-34) 13.3 12.6 15.1 15.6 18.7
Middle aged (35-54) 31.5 32.9 20.3 30.2 33.3
Seniors (55+) 29.8 33.3 20.0 33.1 28.0
Total 100.0 100.0 100.0 100.0 100.0

Ratios

It is sometimes better to divide values by some measure of 'size' before analysis or display.