2. Plot the percent change from a year ago of the Dow Jones Industrial Average (FRED code: DJIA). Discuss the behavior of changes in the index before, during, and after recession periods, which are indicated by the vertical, shaded bars in the graph. (L02) Hint: Continuing from where you ended Data Exploration problem I , change the \"Units\" dropdown box from \"Index\" to \"Percent Change from Year Ago; \" change the \"Frequency\" dropdown box to \"Monthly\" from \"Daily; \" and select \"Redraw Graph.\" Changing to \"Percent Change from Year Ago\" highlights the swings in the index, while using the monthly frequency averages out daily uctuations that obscure the big pattern