3 An expert tested the quality of the wines produced by a vineyard in 9 particular years. He placed them in the following order, starting with the best.
$$\begin{array} { l l l l l l l l l }
1980 & 1983 & 1981 & 1982 & 1984 & 1985 & 1987 & 1986 & 1988
\end{array}$$
- Calculate Spearman's rank correlation coefficient, \(r _ { s }\), between the year of production and the quality of these wines. The years should be ranked from the earliest (1) to the latest (9).
- State what this value of \(r _ { s }\) shows in this context.