|
| Year | Country | PVD* (mm) |
| Bellamy et al. [17] | 1984 | England | 7.2 ± 2.3 |
| Hawaz et al. [19] | 2012 | Ethiopia | 7.9 ± 2 |
| Saha et al. [23] | 2015 | India | 8.83 ± 2.12 |
| Rahim et al. [11] | 1985 | England | 8.76 ± 1.5 |
| Rokni et al. [13] | 2005 | Iran | 8.9 ± 1.08 |
| Rokni et al. [14] | 2006 | Iran | 9.36 ± 1.65 |
| Luntsi et al. [18] | 2016 | Nigeria | 9.60 ± 1.41 |
| Mildenberger et al. [12] | 1987 | Germany | 9.7 ± 1.7 |
| Our study | 2019 | Benin | 9.83 ± 0.95 |
| Lal et al. [7] | 2018 | India | 10.2 ± 1.47 |
| Adeyekun et al. [20] | 2014 | Nigeria | 10.3 ± 1.5 |
| Geleto et al. [8] | 2016 | Ethiopia | 10.6 ± 1.8 |
| Wiersema et al. [16] | 1995 | United States | 10.7 ± 1.7 |
| Gareeballah et al. [22] | 2017 | Sudan | 10.73 ± 1.47 |
| Usman et al. [9] | 2015 | Nigeria | 10.87 ± 0.81 |
| Weinreb et al. [10] | 1982 | United States | 11.00 ± 2 |
| Anakwue et al. [21] | 2009 | Nigeria | 11.45 ± 1.49 |
| Cosar et al. [15] | 2004 | Turkey | 11.68 ± 0.26 |