Year

2012

2013

2014

2015

2016

2017

2018

Cumulative total revenue/total cost $T^{\prime }=0$

0.64

0.88

1.01

1.10

1.16

1.21

1.24

Cumulative total revenue/total cost $T^{\prime }=1$

0.46

0.69

0.84

0.94

1.02

1.08

1.13

Cumulative total revenue/total cost $T^{\prime }=2$

0.36

0.58

0.72

0.83

0.91

0.98

1.03

Cumulative total revenue/total cost $T^{\prime }=3$

0.31

0.50

0.64

0.75

0.83

0.91

0.96