Scraping a table without null data

Hi, I am totally new to scrapign and was having some issues when trying to scrap the table from this site: https://especiales.semana.com/100-empresas-mas-grandes-de-colombia-2018/index.html

Setting the sitemap and selectors seemed to be really easy, but when scraping it returned a lot of null values in all the columns that had numbers instead of letters. How can I fix this issue?

Sitemap:
{"_id":"colombia","startUrl":["https://especiales.semana.com/100-empresas-mas-grandes-de-colombia-2018/index.html"],"selectors":[{"id":"tabla","type":"SelectorTable","parentSelectors":["_root"],"selector":"table#example","multiple":true,"columns":[{"header":"Posición2018","name":"Posición2018","extract":true},{"header":"Empresa","name":"Empresa","extract":true},{"header":"IngresosOp. 2018(en MM$)","name":"IngresosOp 2018(en MM)","extract":true},{"header":"Var%","name":"Var%","extract":true},{"header":"UtilidadOp. 2018(en MM$)","name":"UtilidadOp 2018(en MM)","extract":true},{"header":"Var%","name":"Var%","extract":true},{"header":"Utilidad neta final 2018(en MM$)","name":"Utilidad neta final 2018(en MM)","extract":true},{"header":"Var%","name":"Var%","extract":true},{"header":"Patrimonio 2018(en MM$)","name":"Patrimonio 2018(en MM)","extract":true},{"header":"Var%","name":"Var%","extract":true},{"header":"Región","name":"Región","extract":true},{"header":"Sector","name":"Sector","extract":true},{"header":"Posiciónsector","name":"Posiciónsector","extract":true},{"header":"Posiciónregión","name":"Posiciónregión","extract":true}],"delay":0,"tableDataRowSelector":"tbody tr","tableHeaderRowSelector":"thead tr"}]}