thelance.com has the most pertinent analysis as per their 1/31 report.
R0 is 2.68
Doubling time 6.4 days
Wuhan infections 75,000 as of 1/25
Exponential growth occurring in multiple Chinese cities.
People keep using these other numbers not seeming to realize that these are the PNEUMONIA cases, exclusive of the tens/hundreds of thousands of upper/lower respiratory infected cases from nCoV.
Chinese government consistently states this in their (under) reporting, but no one seems to 'get' this distinction.