I think the actual range is 9 to 15 years, but it's kind of fun scanning the first page of Google News headlines:
Simpson gets 18 years in prison for robbery, kidnapping (TSN Canada)
OJ SIMPSON SENTENCED TO 15 YEARS (ContactMusic)
OJ Simpson sentenced to 16 years in prison for kidnapping and ...(Chicago Sun-Times)
OJ Verdict: What happens in Vegas, stays in Vegas - for 16 years (Radar Online)
I'll wait for an editor to sort it out.