A concert promoter is forecasting this year's attendance for one of his concerts based on the following historical data:

Year	Attendance
Four Years ago	10,000
Three Years ago	12,000
Two Years ago	18,000
Last Year	20,000

What is this year's forecast using the linear trend line for these data?

(Hint: Treat the value from four years ago as period 0, three years ago as period 1, etc.)

		21,000
		22,000
		24,000
		20,000
		23,000