Tables

Most reports and publications use tables to present some information. Such tables often have several rows and columns and may extend over two or more pages, but we initially restrict attention in this section to much simpler tables.

Frequencies

One common type of data is a set of frequencies (or counts) that describe how many items from some group (often people, households, farms or companies) are in each of a set of non-overlapping categories. A table of these frequencies is called a frequency table.

Rice survey

As part of a survey of rice producers in Sri Lanka, 36 farmers were randomly selected from 4 villages. Each sampled farmer was asked about the variety of rice that he used and the varieties were categorised into 'Old', 'Traditional' or 'New'. The 36 resulting categorical values are shown on the left of the diagram below.

To calculate the frequencies for each of the three types of rice by hand, you would work through the table of values, drawing a line against the appropriate category name for each value (a tally). These tallies would be finally be added to give the frequencies.

Click on each of the categorical values in turn to illustrate how the tallies and frequencies are obtained.

The final table of frequencies on the right summarises usage of the three types of rice. The frequency table contains all information about the distribution of rice types.

Drivers killed in New Zealand

The following three frequency tables describe different characteristics of the 190 drivers who were killed in road accidents in New Zealand during 2006.

Age Freq  
10 to 14
15 to 19
20 to 24
25 to 29
30 to 34
35 to 39
40 to 44
45 to 49
50 to 54
55 to 59
60 to 64
65 to 69
70 to 74
75 to 79
80 & over
Unknown
-
27
24
9
12
15
21
16
13
6
11
5
7
3
19
2
 
Total 190
Vehicle Freq  
Car
Taxi
SUV
Van
Truck
Bus
Other
150
1
11
13
14
-
1
Total 190
Month Freq
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
19
12
15
11
18
16
15
20
15
17
9
23
Total 190

Each driver who was killed contributes 1 to exactly one category in each frequency table.

Ethnic groups

Most frequency tables in official statistics publications describe much larger populations of items. The frequency table below describes the ethnic groups of the New Zealand population as specified in the 2001 Census.

Ethnic group Frequency
European
Maori
Pacific peoples
Asian
Other
Not stated or unidentifiable
2,868,009
526,281
231,798
237,459
24,924
150,546
Total 3,737,277

Tanzania drinking water

The next frequency table categorises households rather than individuals. It shows the main source of drinking water for all rural households in Tanzania in the dry season of 2002/3.

Source of drinking water    Frequency
Piped water
Protected well
Protected spring
Unprotected well
Unprotected spring
Surface water
Rainwater catchment
Other
1,093,185
653,451
191,042
1,307,623
701,233
754,539
76,989
27,253
Total 4,805,315