Table 3. Shows which papers in the survey were published in each of the last 6 years.

Year of publication	Papers	Number of papers
2014	Wang et al. (2016), Santhi & Jose (2018), Sarazin, Lebbah & Azzag (2014), Solaimani et al. (2014), Chakravorty et al. (2014), Solaimani et al. (0000), Sarazin, Azzag & Lebbah (2014b)	8
2015	Verma, Mansuri & Jain (2016), Shoro & Soomro (2015), Bhadani & Jothimani (2016), Rotsnarani & Mrutyunjaya (2015), Shobanadevi & Maragatham (2017), Jin et al. (2015), Kim (2018), Bonab et al. (2015)	8
2016	Bhadani & Jothimani (2016), Dave & Gianey (2016), Ajin & Kumar (2016), Baltas, Kanavos & Tsakalidis (0000), Gousios (2018), Assefi et al. (2017), Maheshwar & Haritha (2016), Wang et al. (2016), Sinha & Jana (2016), Kusuma et al. (2016), Backhoff & Ntoutsi (2016), Sharma, Shokeen & Mathur (2016), Zayani, Ben N’Cir & Essoussi (2016), Shah (2016), Bharill, Tiwari & Malviya (0000), Pang et al. (0000), Mallios et al. (0000), Guo, Zhang & Zhang (2016), Hassani et al. (2016), Zhou & Wang (0000), Lulli, Dell’Amico & Ricci (2016)	21
2017	Baltas, Kanavos & Tsakalidis (0000), Salloum et al. (2016), Armbrust et al. (2015), Xu & Tian (2015), Shirkhorshidi et al. (0000), Rujal & Dabhi (2016), Ding et al. (2017), Ben HajKacem, Ben N’Cir & Essoussi (2017), Wu et al. (2017), Gao & Zhang (2017), Lighari & Hussain (2017), Kamaruddin, Ravi & Mayank (0000), Rui et al. (2017), Liang et al. (2017), Sherar & Zulkernine (2017)	15
2018	Othman et al. (2018), Hu et al. (2018), Kim (2018), Xin et al. (2013), Zerhari, Lahcen & Mouline (2015), Sood, Akshay & Singh (2019), Jiang et al. (2010), Shanjiang et al. (2018), Huang et al. (2017), Ketu & Agarwal (2015), Ben HajKacem, Ben N’cir & Essoussi (0000), Chitrakar & Petrovic (2018), Thakur & Dharavath (2018), Lee & Kim (2018), Luo et al. (2016), Han et al. (2018b), Han et al. (2018a), Kim et al. (2018), Baralis, Garza & Pastor (2018), Aryal & Wang (2018), Gong, Sinnott & Rimba (0000), Wang & Qian (2018)	22
2019	Aziz, Zaidouni & Bellafkih (0000), Win et al. (2019a), Fatta & Al Ghamdi (2019), Zhang et al. (2019), Win et al. (2019b), Liu et al. (2019), Lavanya, Sairabanu & Jain (2019), Hosseini & Kiani (2018), Corizzo et al. (2019), Hosseini & Kourosh (2019), Hasan et al. (2019), Sembiring, Jasni & Embong (2010)	12
2020	Ianni et al. (2020)	1