Trends in Yield Tests conducted by AWTA Ltd
Weight by Seasons 1991/92 - 2007/08
Figure 1 shows the progressive weight of wool tested by AWTA Ltd for select seasons between 1991-92 and 2007-08 and illustrates the progressive decline in wool production during this period. Data for the period 1991 to 2001 is graphed with dotted lines where as the more recent data is graphed with solid lines. As of the end of June 2008, the volume tested (based on weight) was 7.0% less than the same period in 2006-07. A table detailing the year on year monthly comparisons for 2006/07 and 2007/08 is provided below Figure 1.
Figure 1

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Historical Trends (1991/92 - 2007/08)
AWTA Ltd's Key Test Data reports are widely distributed and reported. Virtually 100% of all wool shorn in Australia is tested by AWTA Ltd prior to sale.
The AWTA Ltd data includes all auction wools and the majority of privately purchased wools. The latter is not included in the AWEX auction statististics.
The Key Test Data Report reflects the situation at the end of each month in a given financial year, compared to the same period in the previous financial year. Projecting forward to the end of the financial year from these data requires assumptions to be made about the testing pattern over the remaining months.
Historically, the testing distribution over any one year has usually reflected the distribution over the previous year(s), but the exact proportions tested every month do vary, depending upon factors such as the weather during shearing, wool prices, and drought.
The average distribution, for the period 1991-92 to 2007-08, based on weight, is shown graphically below.
Figure 2

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The dashed lines above and below the solid line representing the average are the Upper Control Limit (UCL) and Lower Control Limit (LCL). These simply represent the range of variation that may be observed - the proportion tested can be expected to fall between the UCL and LCL 95% of the time.
A similar graph, representing the progressive distribution, follows.
Figure 3

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