Financial analysis in the business plan

I have a typical problem in the current business where I am the sales and marketing manager. My current turnover is $7M. My employers are asking for a growth of 20% for each of the next two years. I have been asked to show a Gross Profit of 20%. In my opinion it is quite a difficult task, but am forced to accept it.

1. Now how do I justify this growth in my proposed plan?

2. The nature of business is healthcare which includes pharmaceuticals, Over The Counter consumables, agency products, etc.

3. Revenue stream includes: OTC retail, wholesale, agency distributors, veterinary distributors, consumables, Govt. tenderings etc.

4. The growth has to be shown on a quarterly basis for the next two years.

Can you suggest the correct methods of justifications on the growth and the GP? I would appreciate that.