In which year the percentage increase in total number of students is the lowest in comparison to its previous academic year?

total number of students in 2013-2014=150+100=250

total number of students in 2014-2015=200+100=300

total number of students in 2015-2016=300+50=350

total number of students in 2016-2017=250+100=350

total number of students in 2017-2018=300+100=400

percentage increase in total number of students in 2014-2015= $$\frac{300-250}{250}$$*100=$$\frac{50}{250}$$*100=20%

percentage increase in total number of students in 2015-2016=$$\frac{350-300}{300}$$*100= $$\frac{50}{300}$$*100=16.66%

percentage increase in total number of students in 2016-2017=$$\frac{350-350}{350}$$*100= $$\frac{0}{350}$$*100=0%

percentage increase in total number of students in 2017-2018=$$\frac{50}{350}$$*100= $$\frac{50}{350}$$*100=14.28%

from above calculation, percentage increase in total number of students in 2016-2017 is lowest.