An economist gathered data for several economic periods to calculate how the GDP growth rate correlated with other economic variables. The results are below: GDP growth rate (Pearson correlation GDP grow rate 1 treasury bill rate .208 dollar exchange rate -.075 bond rate .045 inflation rate -.385), (Sig. 2-tailed treasury bill rate .564 dollar exchange rate .837 bond rate .901 inflation rate .272), (N GDP grow rate 10 treasury bill rate 10 dollar exchange rate 10 bond rate 10 inflation rate 10). With which other variable is GDP growth most closely correlated