Although you don't expect it, plotting the below graph is a bit tricky on Google Spreadsheet, since the vertical axis goes from the largest to smallest as the bottom to top.
To do this, we need to change the "appearance" of the values in a column.
This can be achieved by applying, format -> number -> more formats -> custom formats on Google Spreadsheet, after you select a column of your spreadsheet.
For the above plot, I used "-0;0".
