Trying to map some negative percentage values in QGIS. Working with a .xls table and importing this as a vector file to QGIS, then joining the file with a shapefile. Have converted negative percent values "to real" and any leading zeroes have been eliminated. Despite this, after the conversion "to real" in the field calculator, the attribute table shows a column of single zeroes in place of my negative values. Cannot convert to integer, as the loss of precision would mess up everything.