Survey question: cetificate renewal frequency

[Dave S]

For those of you with paid-for certificates for your site(s), how often to you have to renew your certs?  For Let's Encrypt, the cert expires in 90 days.  Since renewal with Let's Encrypt can be automated, I don't consider that a painfully short period, but when talking to my bosses I'd like to be able to say how that compares with other CA vendors.

Dave
/dps