Data is latest version of Gisstemp LOTI (land ocean temperature index). This is currently at
https://data.giss.nasa.gov/gistemp/tabledata_v4/GLB.Ts+dSST.txt
or
https://data.giss.nasa.gov/gistemp/tabledata_v4/GLB.Ts+dSST.csv
if you prefer csv file.
January to May 2023 were not hottest for those months but June 2023 was. So it may seem that 7*14=98 is the highest possible value. However it is not impossible that the numbers get revised so theoretically possible for it to be 8 months or more in which case the maximum will be capped at 100% because cannot resolve at more than that.
This is virtually certain to resolve to 98%. The linked data already shows that Jun - Oct were the hottest ever, and even though it's not listed on the NASA website, November was also the hottest ever (in fact, every single day in November was the hottest ever for the full time we've had data for individual days: https://climatereanalyzer.org/clim/t2_daily/?dm_id=world). And December is on track to be way hotter than any previous December.