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

$\backslash$table$[[$Years$,$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 exponential smoothing with alpha $=\mathrm{.}2,$ if last year's smoothed forecast was $15,000?$