How do I do that? There's no obvious way to change the solution. Previously the answers were not specific enough to be useful to other people with the same problem, but Ballard has now posted a more detailed answer which will work. ... View more

*mean of age for participants in study years “1999-2004”, “2005-2010” and “2011-2014” in Table 1; This line in your code means you're copying and pasting your code, likely from a Word document. It's adding 'smart quotes' and may also be adding other invisible characters affecting your code.  Try typing the code out from scratch and see if it works.    Also, you can turn off that feature - see the link above.  ... View more