Using the RANK function to rank decimal numbers

I'm trying to rank numbers that contain decimals, example starting with 100 to be ranked as 1 and the rest in descending order, such as 99.5, 98.7, 80.2, 50.1, etc. There are also more than one of several numbers, such as 3 that are 50.1 as an example. Using the Excel help I get the idea that I should use RANK.EQ as the function and they give an example for tie breakers. but it doesn't seem to work with decimal numbers. Is the RANK function for whole numbers only????? If so, is there any other functions to use to rank decimal numbers. The reason I'm using decimal numbers is because there would be many replicates of the same whole number and the ranking seems to be useless then. Any help would be greatly appreciated.

Thanks everyone for you quick responses. Unfortunately I have to go to a rather lengthy meeting, till after lunch, so I won't be able to respond with samples, etc. or test the *=IF(......* that you sent to me. I will try to respond back tomorrow morning. Thanks again!

Below is a sampling of the data and the ranking I get with the Function: =RANK.EQ(N5,$N$5:$N$71,0), this is only a sampling of the data. BTW, I tried the above *=IF(......* and got identical results for the rank.
% Completed Ranking Based on % Completed
100.0 1
100.0 1
100.0 1
80.0 4
71.4 5
69.8 6
66.7 7
66.7 7
60.0 9
58.3 10
57.1 11
55.6 12
55.0 13
54.5 14
54.5 14
53.2 16
50.0 17
50.0 17
50.0 17
50.0 17
50.0 17
50.0 17
46.2 23
42.9 24
41.7 25
40.0 26
40.0 26
40.0 26
40.0 26
37.5 30
35.0 31
33.3 32
Don't know why the data doesn't paste correctly under the column headings. Giving the three 100 values a rank of 1 is okay, but would like the next value of 80.0 to have a rank of 2 and so on down the line for the other same number multiples, instead of skipping to 4 if this is at all possible??? If this is a good as it gets then I can deal with that, just hoping for a better solution.

Worked exactly as requested! Thanks Tony!