Just over a hundred currently.
We send about 160 - a generational thing, plus with work we've moved around a lot and I'm still in touch with lots of people from my childhood.
We always buy charity cards and recycle as much as possible, including stamps, and making Xmas tags etc. It's really lovely to hear from people we are only in touch with once a year, and I write personal notes to many of them, and get replies which are proper letters and with meaningful news and such. Obviously some are just "To Gnomeo, from Whoever" but it's a fairly harmless way of connecting with people at this time of year. Most people I send to aren't on social media or I don't know their email, and having a card with a bit of news in it helps me to think about them more.