I thought that was what I just did. 18 known malware for the Mac OSX system that can attempt to "trick you into installing it" only to have the System itself warn you about it without installing any anti-malware from a third party... Vs. Thousands of malware on Windows that requires you install a third party anti-malware coat of armor for protection.
That makes the ratio of malware to installed base roughly the same, lending credcence to the observation that there’s less of it written for the Macs because there are fewer of them.