| N (비중: %) | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 전체 |
|---|---|---|---|---|---|---|---|---|
| 수확불변 | 10 | 7 | 4 | 8 | 7 | 4 | 10 | 49 |
| (9.62%) | (6.73%) | (3.85%) | (7.69%) | (6.73%) | (3.85%) | (9.62%) | (6.73%) | |
| 수확체감 | 16 | 26 | 0 | 10 | 9 | 2 | 12 | 76 |
| (15.38%) | (25.00%) | (0.00%) | (9.62%) | (8.65%) | (1.92%) | (11.54%) | (10.44%) | |
| 수확체증 | 78 | 71 | 100 | 86 | 88 | 98 | 82 | 603 |
| (75.00%) | (68.27%) | (96.15%) | (82.69%) | (84.62%) | (94.23%) | (78.85%) | (82.83%) | |
| N | 104 | 104 | 104 | 104 | 104 | 104 | 104 | 728 |