Ranking by Percentage of Contribution to Category

Okay you all were kind enough to help me out yesterday and I appreciate that, so today I want to see if anyone can help with this thought.

I have a 30,000 line spreadsheet that contains approximately 150 different grocery product categories. I am wanting a formula that will rank each item, within each category, by it's percentage of contribution to the total category units sold. I have attached a simple example of what I am looking for, I hope it makes sense. Please note that the spreadsheet has no breaks that would separate the categories, so the formula will have to be able to know when one category stops and another begins.

Thanks so much for your help!!

Column D, Percentages:

=C3/SUMIF($A$3:$A$25,A3,$C$3:$C$25)

Column E, Rank by Contribution

ASCENDING RANKS

=COUNTIF($A$3:$A$300,A3)-((SUMPRODUCT(($A$3:$A$300=A3)*($D$3:$D$300>D3))+1)+COUNTIFS($D$3:D3,D3,$A$3:$A3,A3)-1)+1 (Array - Ctrl+Shift+Enter)

or

=SUMPRODUCT(--(A$3:A$25=A3),--(D3>D$3:D$25))+1


DESCENDING RANKS

=COUNTIF($A$3:$A$300,A3)-((SUMPRODUCT(($A$3:$A$300=A3)*($D$3:$D$300<D3))+1)+COUNTIFS($D$3:D3,D3,$A$3:$A3,A3)-1)+1 (Array - Ctrl+Shift+Enter)

or

=SUMPRODUCT(--(A$3:A$25=A3),--(D3<D$3:D$25))+1

You guy's are awesome!!

I have tested the formulas on a smaller version of my spreadsheet and they appear to be working perfectly. I will try it on the full spreadsheet later today and let you know the results.

Thanks again!

Okay all appears to be working great. Now I would like to add one more column that shows the Cumulative Sales Percentage. Meaning that I need a formula to add the percentage totals together until it reaches 100. I know how to do the Cumulative formula for one category, but with multiple categories in one spreadsheet I am unclear on what to do.
I have attached the example.

Thanks!

Perfect!! Thank you!