GDP growth rate in R

Question

I’m using the code

pib <- BETS.get(22099)

To pull the GDP, turns out he pulls from 1995 to 2017, and I just need 2007,01 à 2013,12. How do I pull only the period I need for the model? Because then I need to use the code

dpib <- (((pib+lag(pib,-1)+lag(pib,-2)+lag(pib,-3))/4)/
  ((lag(pib,-4)+lag(pib,-5)+lag(pib,-6)+lag(pib,-7))/4)-1)*100

To know what was the variation of GDP in the period. Thank you.