You can use part-time equivalent experience. Read the application guide, p.6:
http://www.cic.gc.ca/english/pdf/kits/guides/EG7.pdf
"You must have at least one continuous year of full-time, paid work experience or the equivalent in part-time continuous employment."
To determine equivalent experience, you will have to calculate the experience based on a definition of full-time as 1950 hours per year. (37.5 hours per week * 52 weeks in a year).