The authors regret that errors were present in the above article; references in the text to some of the Figures were incorrect.
Reference in the text to Figure 2 should refer to Figure 4.
Reference in the text to Figure 3 should refer to Figure 2.
Reference in the text to Figure 4 should refer to Figure 3.
The Figures and their legends are correct.
The authors would like to apologise for any inconvenience caused.
DOI of original article: 10.1016/j.bjae.2020.01.004.
