The given data is a time series data for three years divided into quarters. The data for each quarter of each year is as follows:

For Year $1$:

Quarter $1$: $5$

Quarter $2$: $2$

Quarter $3$: $1$

Quarter $4$: $3$

For Year $2$:

Quarter $1$: $8$

Quarter $2$: $4$

Quarter $3$: $4$

Quarter $4$: $6$

For Year $3$:

Quarter $1$: $10$

Quarter $2$: $8$

Quarter $3$: $6$

Quarter $4$: $8$