I have data on emissions changes across states over time. The emissions are normalized as a percent change from the first year of the data set. The percent changes across states are considerably different (some hovering near zero change for the entire period, while others see fluctuations of ~200 percent). When I create a line graph for changes in emissions over time by state using the by() option, states with smaller percent changes appear nearly flat. Is there a way to create line graphs using the by() option that allows for different yscales for each graph?