What is correct style for displaying dollar figures in a column in a table?

I have a table of two columns. One is list of expenses (or revenue). The other is dollar figures.

Should the dollar sign ($) appear with every figure? Or should I put it only with the figure on the first line and again with the sum (as I believe I was taught years ago in school)?

See the sample I posted (as a response to another question) before I was advised to start a new thread: How to format tables with monetary data?

Thanks.