SC24 annual sunspot maximum was reached in 2014,
Data can be found on the website of the World Data Center for the sunspot index
data entry for 2014 shows
Equation tracking sunspot cycles envelope was published on the 7th January 2004 (more than 10 years before SC24 hit its maximum annual value).
Details can be found on the CERN server, the link is
The MS Excel ready formula is on page 3, just above ‘Conclusion’
Vukcevic formula can be copied directly from the page 3, pasted into Excel spreadsheet. When the Ax variable (relevant year) is replaced by 2014 the calculated result is 78.8943 or rounded off to one decimal place
More solar charts can be found here: Graphs and Formulae