Great Idea!  I also just this morning wrote the Governor on the benefits of home gardens and what a perfect opportunity to teach children how to care for our earth and how to grow their own food. 

Here is the link to an article from MSU Extension regarding gardening and young children: https://www.canr.msu.edu/news/gardening_with_young_children_helps_their_development

The National Gardening Association did not have statistics however they have a COVID-19 Gardening statement:

Why garden during a coronavirus lockdown?

Gardening during a pandemic is for everyone, regardless of whether you live in an apartment or on a 100 acre ranch. Victory Gardens during WWII supplied homes with fresh vegetables, fruits, and herbs, and Pandemic Gardens today can do the same. Gardening also gets you out in the fresh air (while respecting social distancing), adds positive energy into your life, gives you something fun to do, and gives a new activity that the whole family can participate in.Through these unpredictable times, let's grow together .   

Here is the link to their website: https://garden.org/covid19/

 Victory Gardens were encouraged during war times for moral and to lower the cost of vegetables: https://en.wikipedia.org/wiki/Victory_garden

Here are (2) links to Michigan statics for farming and crops:

 Michigan Food and Agriculture Systems Profile by County:  https://www.michigan.gov/documents/mda/County_Food_System_Profiles_292923_7.pdf

 Michigan Vegetable Council Industry Facts and Stats:

http://www.michiganvegetablecouncil.org/industry-facts--stats.html

I am disappointed not to have hard numbers for you. I will re open your question if I find any additional information. I hope some of what  provided will be helpful. Thank you for using Ask an Expert.

Thanks, Tracy! Not knowing the number means it's an excellent opportunity for a grad student to document and compile.
I'm going to continue to get my garden ready for planting.  I do have seeds. I'm confident by mid May, well be back up and running,  in full swing but still physically distant. 

Thank you for all the information.  I have read most of it, but it was nice to reread it. 
Have a nice weekend and enjoy the sun!

I reached out to Rebecca Finneran, MSU Extension Senior Horticulture Educator and this is her response: