How much silver is in Canadian coins?

Could you please clarify for me the exact quantity of silver present in Canadian coins? I'm particularly interested in knowing if there are any specific denominations or years in which the silver content may vary. Additionally, is the silver content in Canadian coins still significant today, or has it been phased out in recent years? It would be helpful if you could provide an overview of the historical context and any recent changes to the composition of Canadian coins. Thank you for your time and expertise in this matter.