Muphry's law in action. On the second-to-last, they moved a comma (wrongly), and completely missed the major typo (possibly just autocorrected back to the wrong thing). It should be: "over, say, 50 yo" ("yo" being short for "years old"), and the other half should always have a comma after "30" (the one after "say" is optional depending on where they put pauses when they speak).