Seasonal Kendall Test for Trend
       US Geological Survey, 2005

 Data set:   Example SK1a - Seasonal Kendall test, input type 1         

 The record is 12 complete water years with  12 seasons per year
    beginning in water year 1974.

 The tau correlation coefficient is -0.092
     S =    -22.
     z =  -0.934
     p =  0.3505
     p =  0.3580 adjusted for correlation among seasons
                 (such as serial dependence)
 The adjusted p-value should be used only for data with
    more than 10 annual values per season.

 The estimated trend may be described by the equation:

    Y =   488.0     +   -6.333     * Time

    where Time = Year (as a decimal) - 1973.75 (beginning of first water year)