I have three columns of data, each contains data of a different year
Y2015 Y2016 Y2017 131 234 234 442 490 234 1231 543 123 1231 888 111 123 3333 333
I would like to apply graduated symbols with the "Quantile" mode to the map, and classify the symbols based on values from all three columns, i.e. but it seems that QGIS only allows me to do it based on one selected column.
I cannot adjust the ranges manually either, since I don't know how to calculate the "Quantiles"in Excel.