import numpy as np

# Semiannual returns

returns $=$ np$.$array$([-2\mathrm{.}23,3\mathrm{.}24,1\mathrm{.}24,-0\mathrm{.}64])/100$

# Calculate standard deviation

std$\_$dev $=$ np$.$std$($returns$)$

# Annualize

annualized$\_$std$\_$dev $=$ std$\_$dev $*$ np$.$sqrt$(2)$

# Convert to percentage

annualized$\_$std$\_$dev$\_$percent $=$ annualized$\_$std$\_$dev $*100$